A breaker doing its job is not a fault. A breaker doing its job repeatedly is telling you something, and the pattern of when it trips usually identifies the cause.
1. Overload
The circuit is drawing more than it is rated for. Classic tell: it trips a few minutes after you turn on the space heater, kettle or hair dryer, and never at any other time. Fix by moving load to another circuit, or by adding a dedicated circuit for the appliance.
2. Short circuit
Hot touching neutral or ground. Tell: it trips instantly, every single time, the moment you reset. There may be a bang, a scorch mark or a smell. Stop resetting it. Repeatedly closing a breaker onto a short is how faults become fires.
3. Ground fault
Current leaking to ground. Tell: a GFCI outlet or breaker trips, usually in a kitchen, bathroom, garage or outdoor circuit, and often after rain. Frequently an outdoor receptacle with water in it, or a failing appliance.
4. Arc fault
AFCI breakers detect the signature of arcing. Tell: a bedroom circuit trips with no obvious load pattern. Sometimes it is a genuine damaged conductor — a nail through cable, a back-stabbed device working loose. Sometimes it is a nuisance trip from a particular appliance's motor. Either way it needs tracing rather than swapping to a standard breaker.
5. A failing breaker
Breakers wear out, particularly after many trips. Tell: trips at loads it used to carry fine, feels warm at rest, or does not reset with a satisfying snap. Cheap to replace — but only after ruling out the causes above, or you have replaced a symptom.
6. Shared or loose neutral
Multi-wire branch circuits with a compromised neutral produce strange, intermittent behaviour across two circuits at once, sometimes with flickering to match. This is the one people live with for years, and it is worth taking seriously.
When to stop and call
Instant trip on reset, any burning smell, any scorch mark, any warm outlet or panel, or a main breaker tripping — stop resetting and call an emergency electrician.
Everything else is fair game for the process above. If the pattern does not fit any of these neatly, that is exactly the intermittent-fault case that proper troubleshooting exists for.