Fighter, Barbarian, and Paladin

[Quadsword]

Can someone more experienced with D&D offer a good summary of these 3 classes and how they compare to each other?

[Yojo0o]

Barbarian: Angry, unrefined brawler. Usually wears medium armor, may wear no armor and make use of an unarmored defense feature. Usually wields the biggest two-handed weapon they can find. Known for having generally the highest effective HP pool in the game, by virtue of being the only class with a D12 hit die and usually taking only half damage due to their Rage feature.

Fighter: Generally a more refined brawler, with fighting style and technique. Versatile, and may specialize in several different ways, including a subclass that gives them spell slots. Could reasonably make use of any weapon. Usually seen in heavy armor, though can be built dexterity-based for light or medium armor instead.

Paladin: Refined knight associated with a powerful oath that provides them with magical power. Fewer mundane features compared to Barbarian or Fighter, replaced with spells and magical features instead. Capable of huge burst damage with Smite, as well as magical healing. Virtually always in heavy armor. Melee-focused, will generally either use a big two-hander or a one-hander and shield. Charisma-scaling, which results in them working well as the party diplomat/face man.

[Doc]

Barbarian; Rage is a key mechanic, more HP than the others, gains some resistances and more damage output while raging, has some features that allows you to hit better, but enemies will also hit you better in return. For flavour think brawlers, berserkers, etc. Good at it's job, which is combat. Values strength. Also no heavy armor. Very straight forward, you want to tank damage and kill things, and the subclasses either make you tankier or help you kill things better.

Fighter: very versatile, can be built for both melee and ranged combat, proficient in all weapons and armor, can be specialized further with subclasses, can be either strength or dex based, your choice. In general pretty vanilla, but also pretty easy to learn and it gets the job done. Think, your average soldier/dude in armor. Subclasses can change the strengths a bit, like getting a little bit of spellcasting, or maneuvers you can use to control the battlefield more.

Paladin: Knight with divine powers, can be built with either strength or dex, but no benefits if you want to go ranged. Has an oath with rules and whatnot and some spells associated with each one. Has some limited spellcasting which uses Charisma. Can smite enemies for extra damage, though not as versatile as the fighter with regards to combat role and fighting styles (no dual wielding or archery for example). Gets some auras later on that can support and buff the party.

They're all solid and work well as frontliners, but the extra utility they offer is different.