i just downloaded a bunch of texture packs, and in the install instructions it says

extract the contents, there should be a folder named cncr04sp2
it must be extracted into \half-life 2\hl2\materials
or \half-life 2 deathmatch\hl2mp\materials
or \day of defeat source\dod\materials
or \counter-strike source\cstrike\materials
If you have steam you might have to go into your steam dir and
find these folders. After you extract you can begin to use the
textures.

well i don't have a materials folder. Should i make one for every mod and such ? Right now im going to make my first half life map, then i guess a cs map, then dod, so i want these texture packs in all of my folders. is that how i go about it ? Just add the packs to each folder's "materials" folder ? THank You.

The models themselves (files with an extension of .mdl) should go in your [insert game here]\models\cncr04sp2 folder. If there isn't a models folder, make one. Texture files (files with .vtf and .vmt extensions) should go in [insert game here]\materials\models\cncr04sp2. Once you've done that, restart the SDK, and your models should load correctly in Hammer/Model viewer. If your models look like they have purple and black checkerboxes on them, your textures are in the wrong folder.

what do you mean by restarting sdk.

to be honest, i don't understand how this works, these textures, by placing them how you say, have no way of coming to use in hammer. because they are not .wad, and rather a folder filled with sub folders, that have all these different files in them, i don't understand how it is hammer will be able to use them.

Is this where the SDK comes in ?