The Brawler is a Pathfinder class found in the Advanced Class Guide. Like its fellows, it's essentially a rip-off of the hybrid classes of D&D 4th edition; in this case, it's a fusion of Fighter and Monk with added "Good Old Fisticuffs!" flavoring. The result is a tough and hardy thug who specializes in beating people to death with their bare hands, but without the Monk's trademark "must be Lawful" bullshit.
In a bit more words, he gets the versatility of feats of both a Monk and a Fighter (including the power of using Feats they know nothing about) with the unarmed kickassitude of the Monk without any of that Alignment malarkey or ki pool resources and the ability to actually do things beside punch. He has Flurry of Blows and the power to knock out bitches, but can actually use armor and other weapons.
Archetypes can add some special properties to mess with, like the Mutagenic Mauler delivering the usage of the Alchemist's mutagens, the Shield Champion turning the Brawler into Captain America, the Wild Child grants the ability to be a non-magic Ranger that's less crap...and then there's the Strangler, an archetype that trades Flurry of Blows and knockout abilities for the singular ability of being exceptionally good at choking bitches. And that's hilarious enough to see once.
Brawl is Tier 4. They can smash things, improvise ways to smash things better, and overcome some physical obstacles but that's about it.
|The Classes of Pathfinder|
|Core Classes:|| Barbarian - Bard - Cleric - Druid - Fighter - Monk |
Paladin - Ranger - Rogue - Sorcerer - Wizard
| Alchemist - Antipaladin - Cavalier |
Inquisitor - Oracle - Summoner - Witch
| Arcanist - Bloodrager - Brawler - Hunter - Investigator |
Shaman - Skald - Slayer - Swashbuckler - Warpriest
| Kineticist - Medium - Mesmerist |
Occultist - Psychic - Spiritualist
|Ultimate X:||Gunslinger - Magus - Ninja - Samurai - Shifter - Vigilante|