The vocabulary of the cloud bill, defined in one paragraph each.

Each term below is defined in a paragraph short enough to quote, then explained, then linked to the guide that covers it properly.

Chargeback: Chargeback is the practice of allocating cloud costs to the departments, products or customers that caused them and then billing those costs to their budgets, usually as an internal recharge or intercompany invoice. It is showback with consequences: the same allocation, but the consumer’s budget changes when the statement is posted.
Cloud cost allocation: Cloud cost allocation is the assignment of every line of a cloud bill to the department, product, customer or service that caused it. Three methods apply in order: direct allocation by account, project or tag; proportional allocation of shared costs by a measured driver; and fixed allocation by an agreed split. What remains is reported as unallocated, and the total reconciles to the invoice.
Cloud cost anomaly: A cloud cost anomaly is spend that departs from what the history and the plan said to expect for a service, an environment or an owner: a service that doubled overnight, a region that appeared, a commitment that expired into on-demand. It is defined against a baseline, so the same amount can be an anomaly for one service and noise for another.
Cloud cost visibility: Cloud cost visibility is the ability to see cloud spend as it happens, broken down by provider, service, account and time, usually through the provider’s own tools or a dashboard. It answers what was spent, but not whose it was or why it changed, which is where cost transparency begins.
Cloud unit economics: Cloud unit economics is the cost of running a product or service expressed per unit of what the business sells or serves: cost per transaction, per customer, per order, per active user. It is the allocated cloud cost of the product divided by the business volume for the same period, and it is the layer at which cloud spend becomes a business conversation.
Commitment discount: A commitment discount is a reduced price a cloud provider offers in exchange for a commitment to a quantity of usage or an amount of spend over one or three years: reserved instances and reservations, savings plans, and committed-use discounts. The provider applies the discount to matching usage; unmatched usage is charged on demand, and committed amounts with no matching usage are paid for anyway.
FOCUS: FOCUS, the FinOps Open Cost and Usage Specification, is the FinOps Foundation’s open schema for cloud billing data. It defines one set of columns with one meaning across providers, covering billed and effective cost, service and charge categories, resource, account and commitment identifiers, so that AWS, Azure and Google Cloud exports can be read as one dataset.
IT cost transparency: IT cost transparency is the state in which every technology cost can be seen, attributed to the service or business consumer that caused it, and explained in terms that consumer recognizes. It goes beyond visibility, which only shows what was spent, by adding attribution to owners and a trace from any figure to the resources behind it.
Shared costs: Shared costs are cloud costs that serve more than one department, product or customer and so have no single direct owner: Kubernetes and platform clusters, networking and egress, security and observability tooling, support plans, enterprise agreements and commitment discounts. They are allocated by a measured usage driver where one exists and by an agreed fixed split where none does.
Showback: Showback is the practice of reporting to each department, team, product or customer the cost of the cloud resources it consumed, without charging that cost to its budget. The money stays with the central budget that pays the provider; the consumer sees its number, questions it, and agrees the allocation rules before any money moves.
Unallocated cost: Unallocated cost is the part of a cloud bill that no allocation rule could place with an owner or an agreed shared treatment. It has three causes: a missing or invalid owner tag, an account, subscription or project not mapped to an owner, and provider-level charges such as credits or taxes. It is reported by cause with an owner for fixing it, never spread across consumers.