Bots in crypto trading are covered in full in the entry Crypto Trading Bots, which explains common strategies, how bots connect to exchanges and the risks involved. This page gives a short definition and explains how the word is used.
A bot is a software program that carries out tasks automatically according to preset rules. In crypto, most bots trade: they place buy and sell orders on exchanges, run arbitrage between venues, provide liquidity as market makers or follow signals such as price levels and indicators, a form of algorithmic trading. Other bots work directly on blockchains, for example a sniper bot that buys new tokens the moment they launch, or programs that spot and exploit price differences between decentralized exchanges.
"Bots" is the everyday plural used on forums and social media, while "crypto trading bots" names the main category. The word also covers chatbots in Telegram and Discord groups, some of which are used in scams, and fake social media accounts used to promote tokens. Context usually makes clear which meaning is intended.