Extra

Everybody plays one or more of these formats (and if you don't you better start now) standard, modern, legacy, cube, vintage, commander, tiny leaders, and limited. I will go over the ones I know of and tell you what it's about and it's pros and khans (of tarkir). Everything I write will be from personal experience, so if you disagree, or think somethings I wrote are false please tell me in the comments. 

Standard (Once upon a time, I played this format. Then mono black rotated and I lost $50, so I quit.) 

Standard is a format with all the regular deck building rules, except for the fact that you may only play certain sets cards. Until Battle for Zendikar comes out, the sets that can be played are Theros, Born of the Gods, Journey into Nyx, M15, Khans of Tarkir, Fate Reforged, and  Dragons of Tarkir.

Pros : Many people play this and going to your LGS(local game store), you wont have trouble finding an opponent. This format has many tournaments, more than any other format, so your LGS will always have a tournament for it.

Khans: Expensive to play top decks. you may lose a ton of money when it rotates. There are, like all other formats, budget decks, but like all other formats the budget ones are worse than the ones that are not.

Modern (I built a budget version of an infect deck and fell in love of the format, then I got a modern event deck and upgraded both. I think this is the best format of MTG.)

Modern is a format with all the regular deck building rules, except for the fact that you may only play certain sets cards. The sets that can be played are from 8th edition forward.

Pros : Growing format. Wizards of the Coast (makers of MTG) is making a conscious effort to make the format better and more affordable. Does not rotate. Eternal Format. Cheapest of all eternal formats.Many tournaments for this format, popular.

Khans : Expensive, best deck is worth more than $1000. But a good deck can be had for $45 here. 

Legacy (I really have no background in this format, as I don't have the money to play this. This is supposed to be fun, but I don't know.)

Legacy is a format with all the regular deck building rules, and you may play any cards in any Magic set except for cards in this banned list. 

Pros : Many people think the format is fun. Some tournaments for this, but they may be hard to find. Large variety of decks, with none of them really the best. 

Khans : Very expensive, and not very many good budget options. Becoming less popular.

To be continued