Glossary

Quick definitions of terms used across our tools and courses. Click a term for more detail and links.

• APIA defined way for one program to ask another program for data or actions.→
• AuthenticationProving who you are, for example with a password, a key or a token.→
• Base64An encoding that writes bytes using 64 text-safe characters. It is not encryption.→
• Batch APIAn asynchronous endpoint for jobs that can wait, usually billed at a discount.→
• CIDRA notation like 192.168.1.0/24 that describes a block of IP addresses.→
• Context windowThe maximum number of tokens a model can handle in one request, input and output together.→
• CronA Unix scheduler that runs commands at times defined by a five-field expression.→
• DNSThe Domain Name System: the global directory that turns names into IP addresses and other data.→
• EncryptionScrambling data with a key so only someone with the right key can read it.→
• Fingerprint (host key)A short hash of a key, used to check you are talking to the right server.→
• HashA fixed-size fingerprint of data produced by a one-way function.→
• JWTJSON Web Token: a compact, signed string that carries claims between systems.→
• LLMLarge language model: a neural network trained on text to predict the next token.→
• Private keyThe secret half of a key pair. It must never be shared.→
• Prompt cachingReusing a recently processed prompt prefix so repeated input is billed at a lower price.→
• Public keyThe shareable half of a key pair, used to verify signatures or encrypt data for the key owner.→
• Rate limitA cap on how many requests a client may make in a period of time.→
• RegexA pattern language for matching text, short for regular expression.→
• SaltA random value added to a password before hashing so identical passwords get different hashes.→
• SHA-256A secure hash function from the SHA-2 family that outputs 256 bits.→
• SSHSecure Shell: an encrypted protocol for remote login, command execution and file transfer.→
• SubnetA smaller network carved out of a larger IP range.→
• TLSTransport Layer Security: the encryption behind HTTPS and many other protocols.→
• Token (LLM)A piece of text, such as a short word or part of one, that a model reads and writes.→
• TTLTime to live: how many seconds a DNS answer may be cached before asking again.→
• UTCCoordinated Universal Time: the time standard with no daylight saving that other zones offset from.→