Team Fortress 2 - The Basics

Well, for my first post I would like to review a game that I feel is one of the best games out there. Team Fortress 2 is a free to play game made by VALVE, the company that developed Steam, essentially a platform that sells games, links people, and supports a vibrant community workshop.
Team Fortress 2 was made on October 9th, 2007, and so is slightly under 10 years old. It has aged well! The updates as of late have been disappointing, like 'Meet your Match', the part war between the 'Heavy' and the 'Pyro', part casual ranking system, but others have been amazing, such as Sniper vs Spy. This update started off with it being another single class update, but through the course of it,  the Spy appeared in the images... This was the first double class update, but more importantly, it introduced cosmetics!
So... There are nine classes:

Scout:
Primary - Scattergun
Secondary - Pistol
Melee - Bat

Soldier:
Primary - Rocket Launcher
Secondary - Shotgun
Melee - Shovel

Pyro:
Primary - Flamethrower
Secondary - Shotgun
Melee - Fire Axe

Demoman:
Primary - Grenade Launcher
Secondary - Stickybomb Launcher
Melee -  Bottle

Heavy:
Primary - Minigun
Secondary - Shotgun
Melee - Fists

Engineer:
Primary - Shotgun
Secondary - Pistol
Melee - Wrench
Other - Construction/Destruction Menu

Medic:
Primary - Syringe Gun
Secondary - Medi-Gun
Melee - Bonesaw

Sniper:
Primary - Sniper Rifle
Secondary - SMG
Melee - Kukri

Spy:
Primary - Revolver
Secondary - Sapper
Melee - Knife
Other - Invisibility Watch

These are the 'stock' weapons, the weapons that are the default for each class. It would take a very long time to list all of the weapons in the game... There are 135, but some of them are the same weapon, just with different textures and designs. None of the unique weapons cost more than the others. They are all half of a 'scrap', a metal meant to be used for crafting, but instead changed into a currency by the community. There are three scrap in a reclaimed, three reclaimed in a refined, and, at the time of writing, 26 ref to a key. A key is worth approximately £2. The refined to a key ratio changes almost daily!
I realise that this is a very long post, and is only part of this introduction, but most of my posts will be much shorter than this...