is BIG BOSS. He obtained this Title by killing that girl, who happens to be his mother-not-really-mother, so he kind of hates the title of Big Boss. He also goes by Naked Snake. Not to be confused by Venom Snake
who is Big Boss but not really or with Solid Snake
who is the clone-son of Big Boss (The Naked Snake one, not Venom Snake) or Liquid Snake
who is the superior but not really clone-son, who should not be confused with Liquid Ocelot
who is Big Bosses brother but not really Revolver Ocelot
who got possessed by LIquid Snakes Hand (but not really). He is also Big Bosses sort of best friend. Liquid Snake and Solid Snake (especially Solid Snake) should not be confused however with Solidus Snake
who is also their brother-clone-brother. Liquid, Solid Snake and Solidus have no relation to Raiden
who had the codename Snake for a while and worked with Iroquois Pliskin
who is just Solid Snake who used a different codename.
Raiden later becomes a cyborg to be more likeable (because everyone hates MGS2 because Raiden is infact not Snake and the real Solid Snake was working with him but couldn’t use his own codename because Raiden took it) and because he is much more awsome as a cyborg, raiden got his own Spin-off Game that has almost nothing to do with anything in Metal Gear.
Raiden and Big Boss also both have the same first name (Jack), so you shouldn’t mix up Solid Snake (whos name is David, say hi) with either of those two.
Don0303 