.pac and .pcs

[Sir]

I was just wondering, what is the difference between the two files. Specifically, when I download a texture to put on a character, sometimes I'm given a .pac and .pcs, and sometimes I'm only given one. What am I losing by not having both/gaining by having both for a specific texture?

[Weyard]

The fitcharacter00.pac is uncompressed, the fitcharacter00.pcs is compressed. The .pac is significantly larger in filesize due to this. That is the main difference.

Textures in multiplayer are read from the fitcharacter00.pcs normally. Textures are read from the fitcharacter00.pac in single player modes such as Classic/Allstar if I'm not mistaken.
Sometimes, if a fitcharacter00.pac is present and no .pcs can be found, the texture will be loaded from the fitcharacter00.pac instead.

If the fitcharacter00.pac consists of one texture, while the fitcharacter00.pac contains a different texture hack, the character will sometimes load with the fitcharacter00.pac's texture instead. Not sure why. Because of this, it is generally recommended that you only use a .pcs unless the character in question is a transforming character.

Characters that transform (sheik/zelda,pokemon) need a .pac and .pcs because after transforming, the texture/model is then read from the .pac instead of the .pcs. If no .pac is present when transforming, it usually causes a freeze. Sometimes the character will still freeze if no .pac is present.

Generally, texture hacks in the vault only include the .pcs because it is all that is needed. Usually you will only see a .pac included on transforming characters. Although sometimes people will just add both so you can use the character in all modes if wanted.