Glossary
The words, in plain language
Every term the guide uses that a non-engineer might not know. Wherever one appears underlined with dots, hover over it or move to it with the keyboard to see the same definition.
- Active-CPU billing
- The processor is charged only while it is working, not while it waits. Cheap for agents that spend most of their time idle. Read more
- API and SDK
- Ways for a program, rather than a person, to control the provider: create a machine, run a command, delete it. An SDK is a ready-made library for one programming language. Read more
- Cache read
- Tokens the model has already seen in this conversation and can reread cheaply. Agents reread a lot, so this is most of their tokens and much cheaper than new input.
- Cold start
- The wait while a machine is created or woken before it can do anything. From under a second to a minute, depending on the provider.
- Custom domain
- Serving what the machine runs at your own web address, such as agent.example.com, instead of the provider's. Read more
- Disk
- Where files are kept. On some providers the disk survives a stop, on others it is wiped, which is why the guide asks whether files must be kept. Read more
- Egress
- Data the machine sends out to the internet, such as downloads to a user or uploads to another service. Some providers charge per GB; most agents send very little. Read more
- Fork
- Starting one or more new machines from a snapshot, each continuing from the same point. Useful for trying several things in parallel. Read more
- GiB / GB
- Units of memory or disk. A GiB is about 7% larger than a GB; for choosing a provider the difference rarely matters.
- Idle timeout
- How long a machine can sit unused before the provider pauses, stops or deletes it. Short timeouts save money but can break an agent that must answer at any time. Read more
- Included usage
- A monthly plan fee that comes with the same amount, or a set amount, of usage. You pay the fee even if you use less, and pay extra only above it. Read more
- Isolation
- How firmly one machine is kept apart from others on the same hardware. A microVM is a small full computer and is the stronger wall; a container shares more with its neighbours. Read more
- MCP
- Model Context Protocol: a common way to give an AI agent tools, such as reading a calendar or searching a database, served by a small program called an MCP server.
- Memory (RAM)
- The machine's working space while it runs. Lost when the machine stops unless the provider saves it. A browser or a large program needs more of it. Read more
- Per-second billing
- Usage is counted to the second, so a two-minute task costs two minutes. Some providers round up to a minimum first. Read more
- Region
- The part of the world where the machine runs. It matters for speed if your users are far away, and for law if data must stay in a country or the EU. Read more
- Sandbox
- A computer you rent in the cloud, sealed off from everything else, that a program can create, use and throw away. Agents use one so the code they run cannot reach your own machine or other customers. Read more
- Sleep and wake
- The provider pauses an idle machine and starts it again when a request arrives. You pay little while it sleeps, but the first reply after a pause is slower. Read more
- Snapshot
- A saved copy of a machine at one moment, so it can be restored or copied later. Some providers save memory and running programs too, others only files. Read more
- SSH
- A standard way to open a terminal on a remote machine from your own computer. Read more
- Terminal
- A text window where you type commands instead of clicking. Many providers can be set up only this way; the guide says when one cannot.
- Token
- The unit an AI model is billed in, roughly three-quarters of a word. An agent re-reads its instructions and history on every message, so one message can use tens of thousands.
- vCPU
- One share of a processor. More vCPUs let a machine do more things at once; an agent waiting for messages uses a small fraction of one. Read more
- VPS
- A virtual private server: a machine you rent by the month that runs all the time. Cheaper for one always-on agent, but you set it up and look after it yourself. Read more
- Webhook
- A web address that another service calls when something happens, such as a new chat message. It lets a sleeping machine be woken only when needed.
- Zero data retention
- The model provider promises not to store your prompts or replies after answering. This guide prices only model offerings that make this promise.