How can i know the difference between a coldsore and a pimple?

By the way it looks: A cold sore is a basically an ulcer of the skin created by a virus, there may surrounding redness, but there is no come do (a clogged hair follicle or pore in the skin). On the other hand, a pimple is an infection of the clogged skin pore with bacterial overgrowth, leading to abscess (or head) that can be expressed (squeezed). Also distribution of cold sores are different than pimples.