Exchange APIs are a way for traders to access their exchange account programmatically so they can trade without logging into the exchange.
API (Application Programming Interface) is a software interface that allows different applications to communicate with each other. In the world of cryptocurrency exchanges, APIs are used to enable users to interact with the exchange platform programmatically, allowing them to execute trades, view market data, and manage their accounts.
When using an API, users are typically required to authenticate themselves by providing a pair of keys: the API key and the secret key. The API key is a unique identifier that allows the exchange to identify the user's account, while the secret key is a piece of private information that serves as a password to authorize API requests.
This is an API key from Binance exchange