> ## Documentation Index
> Fetch the complete documentation index at: https://docs.costory.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Glossary

> Definitions for FinOps, cloud billing, and Costory-specific terms used throughout this documentation

## Costory Concepts

<AccordionGroup>
  <Accordion title="Billy" id="billy">
    Costory's AI-powered FinOps assistant. Billy analyzes billing data, detects anomalies, generates cost incident reports, and answers cost questions in plain English via Slack. It powers the Digest and executive summaries.

    → Related: [Monthly Cloud Cost Reporting](/automate-reporting/monthly-reviews)
  </Accordion>

  <Accordion title="Explorer" id="cost-explorer">
    Costory's main interface for exploring cloud costs across all connected providers. Supports filtering, grouping by any dimension, multiple metrics, formulas, event overlays, drill-downs, saved views, alerts, and dashboard creation. Not to be confused with AWS Cost Explorer, which is AWS's own native billing tool.

    → Related: [Explorer](/features/cost-explorer)
  </Accordion>

  <Accordion title="Digest" id="digest">
    An automated monthly cost report that breaks your bill into a tree structure, ranks changes by dollar impact, and generates AI-powered summaries for each significant change. Designed to replace the manual monthly cost review.

    → Related: [Monthly Cloud Cost Reporting](/automate-reporting/monthly-reviews)
  </Accordion>

  <Accordion title="Cost Breakdown Tree" id="cost-breakdown-tree">
    The hierarchical structure used in Digest to organize cost data. You configure which dimensions form the levels (e.g., Provider > Account > Service). Nodes auto-expand based on cost impact.

    → Related: [Monthly Cloud Cost Reporting](/automate-reporting/monthly-reviews)
  </Accordion>

  <Accordion title="Dashboard" id="dashboard">
    A saved view made of one or more Explorer widgets. Each widget keeps its own metric, formula, filters, group-by, selected period, and event context.

    → Related: [Dashboards](/features/dashboards)
  </Accordion>

  <Accordion title="Dimensions" id="dimensions">
    Costory reporting fields used to filter, group, allocate, scope, alert, and report on costs. A dimension can merge several native tags or labels into one field, such as `aws:Environment`, `env`, and `environment` into `Environment`.

    → Related: [Dimensions](/features/tagging/dimensions) | [Env Allocation](/use-cases/automated_env_allocation/visibility) | [EKS cost allocation](/use-cases/eks-cost-allocation)
  </Accordion>

  <Accordion title="Virtual dimensions" id="virtual-dimensions">
    Rule-based dimensions whose output values are defined in Costory. For example, a `Team` virtual dimension can route rows where `project_id` starts with `eng-` to `Engineering`, and route everything else to `Platform` without requiring that tag to exist in any cloud account.

    → Related: [Dimensions](/features/tagging/dimensions#virtual-dimensions) | [Shared Cost Allocation](/use-cases/allocate_shared_cloud_sql_database/allocate) | [Reallocate API Costs](/use-cases/reallocate_api_costs)
  </Accordion>

  <Accordion title="Dynamic Allocation" id="dynamic-allocation">
    A virtual dimension option that splits shared costs proportionally based on actual usage data (e.g., storage or CPU usage per team) rather than fixed rules. Used when a shared resource like a database serves multiple teams.

    → Related: [Shared Cost Allocation](/features/tagging/shared-cost-allocation) | [Dimensions](/features/tagging/dimensions) | [Reallocate API Costs](/use-cases/reallocate_api_costs)
  </Accordion>

  <Accordion title="Standard Columns" id="standard-columns">
    Costory's unified billing schema. All normalized fields are prefixed with `cos_` so you can query across AWS, GCP, and Azure using the same field names instead of learning each provider's billing export format.

    → Related: [Standard Columns](/docs/standard-columns)
  </Accordion>

  <Accordion title="Scheduled Report" id="scheduled-report">
    An automatically recurring cost report delivered to Slack, Teams, or email on a weekly or monthly cadence. Created from any saved Explorer view.

    → Related: [Cost Reports](/features/slack-reports) | [Decentralize FinOps](/automate-reporting/decentralize-finops)
  </Accordion>

  <Accordion title="View" id="view">
    A saved configuration of Explorer with specific metrics, filters, group-bys, date ranges, formulas, and event context. Views can be shared, scheduled as reports, or turned into dashboard widgets.

    → Related: [Explorer](/features/cost-explorer) | [Dashboards](/features/dashboards) | [Cost Reports](/features/slack-reports)
  </Accordion>
</AccordionGroup>

***

## Cloud Billing

<AccordionGroup>
  <Accordion title="Cost Allocation" id="cost-allocation">
    The process of assigning shared or untagged cloud costs to specific teams, products, or environments. The central challenge of FinOps. You can't optimize what you can't attribute.

    → Related: [Tag & Allocate Costs](/features/tagging) | [Shared Cost Allocation](/features/tagging/shared-cost-allocation) | [Reallocate API Costs](/use-cases/reallocate_api_costs)
  </Accordion>

  <Accordion title="Chargeback" id="chargeback">
    Billing internal teams for their actual share of shared cloud costs. Money moves between budgets. See also: [Showback](#showback).
  </Accordion>

  <Accordion title="Showback" id="showback">
    Showing teams what they would be charged without actually moving money between budgets. Lighter than chargeback. The goal is awareness and accountability rather than internal billing.

    → Related: [Decentralize FinOps](/automate-reporting/decentralize-finops)
  </Accordion>

  <Accordion title="Unit Economics" id="unit-economics">
    Financial metrics expressed on a per-unit basis: cost per customer, cost per API call, cost per transaction. Answers the question "are we getting more efficient as we scale?" rather than just "are we spending more?"

    → Related: [Unit Economics](/features/unit-economics) | [Relate Costs to Usage](/automate-reporting/unit-economics) | [Unit Economics with Amplitude](/use-cases/amplitude/cost_per_active_users)
  </Accordion>

  <Accordion title="Marginal Cost" id="marginal-cost">
    The cost to serve one additional unit of value: one more user, one more customer, one more request. In cloud terms, production cost divided by your usage metric. Useful for exec reporting because it shows efficiency trends even when total spend grows.

    → Related: [Executive Reporting](/use-cases/what_your_exec_team_wants/value)
  </Accordion>

  <Accordion title="Cost Allocation Tags" id="cost-allocation-tags">
    Tags that cloud providers require you to explicitly activate before they appear in billing exports. In AWS, you must enable them in the Billing console. A common gotcha: you tagged your resources, but forgot to activate the tags for billing, so they don't show up in cost reports.

    → Related: [AWS Setup](/setup/billing#aws)
  </Accordion>

  <Accordion title="CUR (Cost and Usage Report)" id="cur">
    AWS's detailed billing export, the raw data source for AWS cost analysis. A Parquet file that contains every line item of your AWS bill. Costory ingests this automatically once connected.

    → Related: [AWS Setup](/setup/billing#aws)
  </Accordion>

  <Accordion title="Split Cost Allocation" id="split-cost-allocation">
    An AWS feature that breaks down container costs (EKS, ECS) to individual pod labels. Without this, you only see the total cost of the EC2 instances running your cluster, not what each workload costs. Must be enabled in AWS CUR settings.

    → Related: [EKS cost allocation](/use-cases/eks-cost-allocation)
  </Accordion>
</AccordionGroup>

***

## Cloud Pricing

<AccordionGroup>
  <Accordion title="Unblended Cost" id="unblended-cost">
    The sticker price: each resource billed at its standard on-demand rate, without applying any volume discounts or commitments. What you'd pay if you had no Savings Plans or Reserved Instances.

    → Related: [Currency Conversion](/docs/currency-conversion)
  </Accordion>

  <Accordion title="Amortized Cost" id="amortized-cost">
    Spreads upfront commitment payments (Savings Plans, Reserved Instances) evenly across the commitment period. Instead of showing a $36,000 spike on the purchase date, it shows $1,000/month for 3 years. Usually the most useful cost metric for monthly reporting.

    → Related: [Currency Conversion](/docs/currency-conversion)
  </Accordion>

  <Accordion title="Net Unblended / Net Amortized Cost" id="net-cost">
    The same as above, but after applying credits, EDP discounts, and refunds. Represents what you actually pay out of pocket. If your company has negotiated discounts with AWS, this is the number that matches reality.
  </Accordion>

  <Accordion title="Reserved Instances (RIs)" id="reserved-instances">
    A commitment to use a specific instance type for 1 or 3 years in exchange for significant discounts (up to 72% off on-demand). Less flexible than Savings Plans, locked to a specific instance type and region.
  </Accordion>

  <Accordion title="Savings Plans" id="savings-plans">
    AWS's flexible commitment-based pricing. You commit to a consistent amount of compute usage (in \$/hour) for 1 or 3 years and get discounted rates. More flexible than RIs, not locked to a specific instance type. However, Savings Plan discounts can shift between accounts daily, causing misleading cost fluctuations. See [Why Contracted Cost](/docs/savings-plan-cost-fluctuation).
  </Accordion>

  <Accordion title="EDP (Enterprise Discount Program)" id="edp">
    An AWS program where large customers commit to a minimum total spend in exchange for a blanket discount on all services. Typically negotiated annually. Costory's [Contracted Cost](/docs/savings-plan-cost-fluctuation) metric preserves EDP pricing while stripping out volatile Savings Plan discounts.
  </Accordion>

  <Accordion title="Credits" id="credits">
    Discounts or promotional amounts applied to your cloud bill by the provider: startup credits, support credits, migration incentives. Important to track separately in exec reports because they mask true cost trends.

    → Related: [Executive Reporting](/use-cases/what_your_exec_team_wants/value)
  </Accordion>

  <Accordion title="Marketplace Purchases" id="marketplace-purchases">
    Third-party software bought through AWS, GCP, or Azure Marketplace (Datadog, MongoDB, etc.). These show up on your cloud bill but aren't infrastructure costs, often need to be excluded when calculating production cost metrics.
  </Accordion>
</AccordionGroup>

***

## Kubernetes Cost Terms

<AccordionGroup>
  <Accordion title="Requests vs. Limits" id="requests-vs-limits">
    * **Requests**: the resources (CPU, memory) a pod guarantees it needs. Used for scheduling: the scheduler uses requests to decide which node a pod runs on.
    * **Limits**: the maximum a pod can consume before the kernel kills it.

    Costory calculates waste based on requests, not limits, because requests are what you're actually paying for on each node.

    → Related: [K8s Waste Reduction](/use-cases/k8s_waste/visibility)
  </Accordion>

  <Accordion title="Waste (Kubernetes)" id="waste">
    The gap between what your nodes provide and what your pods have requested. Formula: `available resources - total requests = waste`. Costory converts this to dollars using a 9:1 CPU-to-memory cost ratio. If your cluster has 40% waste, you're paying for 40% more capacity than your workloads need.

    → Related: [K8s Waste Reduction](/use-cases/k8s_waste/visibility)
  </Accordion>

  <Accordion title="Waste Ratio" id="waste-ratio">
    Waste expressed as a percentage of total cluster or node pool capacity. The key metric for identifying over-provisioned clusters.

    → Related: [K8s Waste Reduction](/use-cases/k8s_waste/visibility)
  </Accordion>
</AccordionGroup>

***

## Reporting & Analysis

<AccordionGroup>
  <Accordion title="Anomaly Detection" id="anomaly-detection">
    Automatic identification of unusual cost spikes. Costory goes beyond simple threshold alerts by using ML models trained on your historical data, with seasonality awareness and event correlation, to determine whether a spike is genuinely abnormal.

    → Related: [Monthly Cloud Cost Reporting](/automate-reporting/monthly-reviews)
  </Accordion>

  <Accordion title="Event Correlation" id="event-correlation">
    Aligning technical or business events (deployments, incidents, RI purchases, marketing campaigns) with cost timelines to explain why costs changed. Turns "costs went up 15%" into "costs went up 15% after the v2.3 deploy on Tuesday."

    → Related: [Events](/features/events) | [Event Correlations](/automate-reporting/event-correlation) | [Events Setup](/setup/events)
  </Accordion>

  <Accordion title="Budget" id="budget">
    A spending target set for a team, project, or cloud account over a given period. Costory lets you automate budget tracking by combining virtual dimensions with scheduled reports, so stakeholders get alerted before overruns happen, not after the invoice arrives.

    → Related: [Automate Budget Tracking](/use-cases/automate_budget)
  </Accordion>

  <Accordion title="FP&A (Financial Planning & Analysis)" id="fpa">
    The finance function responsible for budgeting and forecasting. The people who will ask you "why did cloud costs go up?" and expect a number, not a Grafana dashboard. Costory helps you speak their language.
  </Accordion>

  <Accordion title="Waterfall Chart" id="waterfall-chart">
    A visualization showing how individual factors contribute to an overall change: which services, accounts, or teams drove a cost increase or decrease. Answers "where did the extra \$10k come from?" at a glance.

    → Related: [Explorer](/features/cost-explorer)
  </Accordion>
</AccordionGroup>