It is a word that has it's root in costume play. It is both a noun and a verb. Cosplay can mean the actual costume, as well as the action of wearing it
Contrary to popular belief, many cosplayers (well over 98%) do not believe they are the characters they are "cosplaying" as. Cosplays are typically worn to anime conventions
. Cosplays are made for the following reasons..
1.) To recreate a 2 dimensional art form into 3-D.
2.) To challenge one's self to create a cosplay. Many of which dont seem possible to physically create, but somehow are.
3.) To show appreciation and/or interest in a certain anime/manga/videogame.
4.) To take pride in a cosplay that looks well done.
5.) Because normal cloth that is shitted out for everyone via mass factories and little kids in china are dull. Cosplays are much more interesting to wear. And each cosplay is one of a kind unique considering the wearer most likely made it him/herself.
6.)It's a Hobby
Reasons why cosplays are worn:
1.) To take pride in ones own creation
2.) To wear something out of the ordinary (societies restrictions on what is allowable to be worn everyday is bland)
3.) To show support and/or interest in an anime/manga/videogame
4.) Self expression. Often the character that is choosen to be cosplayed mirrors the actual person wearing the cosplay. The person's personality is like the character Not the other way around (the person wants to be the character).
5.) To get into the spirit of the son
6.) To have fun
Cosplayers cosplay for the same reasons that...
1.)Sports fans wear jersies and paint themselves for games.
2.)Goths wear all black, punk wear punk cloth, Preps wear tight cloth, "gangstas" wear baggy cloth....
But for cosplayers....A cosplay is worn for 1-3 days out of the year. A limited and restrained form of self expression.
Cosplay is a "HOBBY". Much like a model builder builds models, a person modifies their car, a hunter hunts (when they can buy food instead), a gamer plays games, a sports fan watches sports. A cosplayer cosplays (makes costumes).
For every 7 good cosplays there is one that someone did without putting any effort into. Those crappy cosplays are the ones that are shown on message boards and posted around everywhere. These shit cosplays are what give the rest of the cosplayers a bad name.
(this applies to American cosplay)