API - Application programming interface
An API is a set of programming rules and specifications that allow two software programs to communicate with each other. In the context of trading, an API allows you to access certain features or data from a broker or trading platform. For example, you might use an API to retrieve live market data or to place trades on behalf of your account. Most brokers and trading platforms offer their API, which you can use to build custom trading applications or integrations. In algorithmic trading, an API can be used to initiate orders or collect data that is used to make decisions about trading strategies. APIs are a key component of all automated trading systems.