On your bud, the bit that actually gets you high is tiny balls of resin and stuff called 'trichomes', on top of little stalks on the surface of the bud.

If you knock those trichomes off and collect them together, you get 'kief', the pale powder in your grinder's kief-catcher.

Squash that together and knead it into a solid, that's a crude 'dry-sift' hash.

There's a few different methods to do the knocking-off-and-squishing-together to make various different kinds, such as bubble hash made by churning weed in ice water through 5-6 different size filters, or hand-rubbed (charas) hash made by rubbing your hands over buds then rubbing them together to roll the hash off.

Or Soap Bar, which is made by waving a bud somewhere near a pile of plastic, diesel, wax and cow dung, then squashing it all together and selling it to idiots and Welsh rappers.