Ok, settle in.
Dark souls, there are two forms. There is human form and undead form. Functionally, there is no difference between the two in regards to your ability to fight. You have the same HP, same chance to find items, etc.. The difference is, while human you are able to summon 2 other players to fight alongside you, but another player can also invade your world and attempt to kill you. While hollowed you do not have to worry about being invaded, but you cannot summon other players to aid you in boss battles.
Since I don't like being invaded I just play in undead form most of the time and shift to human (costs a semi-rare item, humanity or be summoned and help the host kill a boss) whenever I need help with a boss. Also, when being summoned into another player's world to fight, you gain souls along with him and they are not at risk. If you die in another player's world you are just sent back to your own with the souls you gained still in tow. Being summoned is a great way to build up a cache of souls/humanity/experiment with methods to kill bosses without putting your own souls as risk.
When you kill enemies/ bosses you get souls. Souls are the currency/XP of the game. At the bonfires set around the world you can trade a steadily escalating amount of souls to level up and get stat points. Once souls are converted into a soul level they cannot be lost through death. When you die in your own world, you drop all your souls. You have one opportunity to touch your bloodstain (it is about 10 paces back from your point of death) and you gain back all your lost souls. If you die before reaching it, they are gone for good. So as long as you are careful in retrieving your bloodstain, death costs you nothing. It is very similar to the mechanic in Diablo 2, only in Dark Souls you don't have to retrieve your body naked, you keep all your items when you die.
Thoughout the world there are bonfires which are the games checkpoints. Rest at the bonfire and it refills your HP, your health flasks, and sets the bonfire as your respawn point, though it also causes all regular enemies in the area to respawn.
Really, there are kinda difficulty settings in Demon's Souls/Dark Souls. Often the hardest part of the game is starting off being unaccustomed to the style of play and weak. The starting classes begin with a variety of skills and equipment some are much easier to start with than others. A starting class of royal in Demon's Souls is practically easy mode as it starts with a spell which can one shot most enemies for the first few levels. Using a weapon and shield is also much easier than having to rely on dodging/rolling as there is much greater room for error.
[quote name='Japakneez']It doesn't make sense to call it vanilla...regular, standard, and basic is good enough. What would chocolate be lol?[/QUOTE]
Nothing. Vanilla is considered base, neutral ice cream, the foundation of all other ice creams. Strawberry is vanilla + strawberries, chocolate is vanilla + chocolate powder/sauce, a sundae is vanilla + X other toppings, etc.