If your home is older and uses fuses instead of circuit breakers, your fuse would "blow" when overloaded.
In newer home construction fuses are not used and instead a circuit breaker protects you. A circuit breaker "trips", or shuts off and stops the flow of electricity through an electrical circuit when it senses more current flowing through it than it's supposed to have.
By tripping, the circuit breaker protects the circuit and its wiring from overheating and causing damage including fire.
The primary reason for a breaker tripping is due to an overloaded circuit. That situation occurs when a circuit has more connected electrical load than it was designed to handle. When the circuit is overloaded the circuit breaker is designed to "break the circuit" to protect the overcurrent situation.
Circuit breakers come in different ratings that determine how much current they will allow to flow through the circuit. For example, if a 15 amp circuit breaker is protecting a 15 amp circuit, then 20 amps of current flows through it (say a hair dryer or small personal heater were being used) and were on that circuit, (even if on different outlets) then the circuit breaker will trip to prevent overheating of the circuit wiring.
Another reason for a tripped breaker is a short circuit.
A short circuit occurs when the hot (black) wire touches another hot wire or touches a neutral (white) wire. Shorts can also be caused if there is a break in a wire or a loose terminal connection on an outlet in the circuit.
Another type of short may occur in an appliance or device, and not in the home wiring at all.
If the breaker trips when an appliance or fixture is plugged in, then that is the likely culprit.
Also referred to as "trip," "popped," "blown."