In many countries, cryptocurrency activity can have tax consequences, but the specific rules vary widely from place to place. This is a general, educational overview only and not tax advice; the details that apply to you depend entirely on your own country and situation.
Broadly, some jurisdictions treat crypto as property, meaning that selling, trading, or spending it can create a taxable event based on any gain in value. Receiving crypto, for example from certain activities, may also be treated as income in some places. Simply buying and holding is often treated differently from selling.
Because rules differ so much and change over time, keeping good records of your transactions is widely recommended, and consulting a qualified tax professional in your country is the reliable way to know what applies. Nothing here should be relied on as specific tax guidance.