The AWS free tier is generous but widely misunderstood. It is a set of specific limits across many services, not a promise that everything is free, and misunderstanding that distinction causes most surprise bills.

Free offers come in three types: always free within limits, free for twelve months from signup, and short trials. The twelve-month offers are the dangerous ones because they end silently.

The most common bill traps are resources left running and forgotten, data transfer charges, and extra services created silently by tutorials.

Set billing alarms on day one, check cost explorer weekly, and keep a list of everything you run. Those three habits keep learning free.