Sometimes you might see a boxer wearing a headguard and a vest in a fight.
These fighters are amateur, which means they don't get paid for boxing. They are normally younger as well, as boxers start out as amateurs.
If an amateur boxer is really, really good they can decide to make fighting their job. This is called turning professional.
In professional boxing fighters get paid for fighting. They do not wear headguards or vests.
There are also more rounds in a professional fight than in amateur ones. Most professional fights are up to 12 rounds long. Amateur bouts are normally four rounds of two minutes.
It is much more common for fighters to be knocked out in professional fights than in amateur ones.
Boxers trying to win world titles are professional. Those competing in Olympic Games and World Championships are amateur.