Basically there are four types of acne outlined on this page - Blackhead, Whitehead, Multihead and Nodule/Cyst.

The core prevention method for each is the same - cleanliness, as the basic ingredient for acne formation is skin pore blockage.

BLACKHEAD
Typically, a single skin pore gets blocked at the surface by a waxy-type of gunk that has an easily seen black top - because it forms at the pore opening, so grim easily attaches itself to the waxy gunk - but a much less apparent clearer tail fills back into the skin pore itself.

WHITEHEAD
Similar to the blackhead in that a single pore gets blocked but in this case, the blockage is usually just below the skin surface under which a small ball develops that is whitish in colour, because the skin protects the gunk-ball from grim attaching to it and therefore it stays whitish.

In addition, clearer fluid soon backs up behind the blockage to make the whitehead protrude up from the skin surface either as a small ball by itself or backed by an often reddish lump that makes the protruding zit more noticeable and painful.

Finally, a deeper secondary waxy build-up can occur which easily makes the pimple reform quickly after the surface head exits the skin in some manner.

MULTIHEAD
Typically, two or more skin pores very close together get blocked at similar times. It is more usually with whitehead-types than blackhead.

NODULE/CYST
The most nastiest of them all.

A fairly broad region of skin pores become blocked just under the surface, possibly with small whiteheads, but more typically with clearish fluid that quickly forms as a lump under the skin, with the skin surface itself quickly becoming more hardened than the surrounding area.

In addition, the fluid seems to be contained within mini-pockets that makes it very difficult to get all the fluid out, no matter what extraction technique is used.

While growing one of these type of pimples is inconvenient enough, they typically love company more than any other form of acne, often quickly forming next to as well as seemingly on top of each other.