Origins are informations on the character's background, but more importantly it's a preset stat build which allows the player to customize their character based on a preferred play style. There are nine possible Origins to choose from during character creation.
To players who are just starting the game without past experience of FromSoft's games, choosing an Origin maybe something that might have a severe impact on the gameplay, however, this couldn't be further from the truth as the only thing that levels do is to allow players to utilize Weapons and Hunter Tools.
There are no perks nor abilities in Bloodborne that are exclusive between classes, because there are no perks or abilities to begin with. It is a stat system that is very simplistic and which allows a more levelled playing field where actual skill in playing the game is rewarded.
With this said, players might be unfamiliar with some of the stat terminology in the game, and so here's a quick rundown of the stats:
Vitality - Stat that governs health, increasing it will increase total HP.
Endurance - Stat that governs stamina, increasing it will increase total stamina, allowing for more sprinting, attacks and dodging before running out.
Strength - This stat allows players to wield larger weapons that focus on dealing more powerful and staggering blows, and it will boost damage if a weapon has scaling on Strength.
Skill - This stat allows player to wield smaller, faster weapons that focus on swift and adaptive combat, favoring mobility over power, and it will boost damage if a weapon has scaling on Skill.
Bloodtinge - This stat allows players to wield better Firearms and will boost damage if a Firearm or weapon has scaling on Bloodtinge.
Arcane - This stat allows players to wield very interesting weapons that focus on dealing elemental types of damage, and will grant them access to various Hunter Tools, which can turn players into the Bloodborne equivalent of a "Cleric" or "Sorcerer".
N.B. There is no way to respec the stats, as such, whenever players level up, they will be stuck with that level forever.
"Ordinary, happy upbringing. All attributes average."
Average stats with higher emphasis on physical weapons.
The stat total for each of the currently known Origins totals to 60, with the exception of the "Waste of Skin" origin, which totals to 54.
Waste of Skin puts players at a large statistical disadvantage compared to other origins, creating a more challenging experience for the player in early sections of the game. But it is also considered one of the most customizable class, since you can assign points from an earlier level, it allows for greater specialization.
However, if players wish to completely abstain from any special Weapons or Hunter Tools, focusing therefore only on pure Physical sources of damage, then the best Origins are doubtlessly either the "Violent Past" or "Military Veteran" as they have the absolute minimum points in Bloodtinge and Arcane, thus allowing more points to be put into other stats without having the need to level up as much.
The "Military Veteran" Origin is considered a great class for beginners as it allows players to a wield a vast selection of weaponry from the beginning of the game, while focusing stat investment mostly on Vitality or Endurance.
The "Waste of Skin" Origin has, hilariously enough, just the right amount to purchase a single Pebble from the Bath Messenger.
It has been theorized that, lore-wise, the player character's true origin might be all of the non-conflicting origins merged together, that is to say, all of the origins except "Milquetoast" and "Waste of Skin".