Anyone know what is a stye and how can it be treated?

Chalazion: A stye or chalazion is a occluded oil gland(meibomian gland, similar to sebaceous gland in the skin). A stye develops when the oil gland gets plugged up from dust, debris, makeup, animal dandruff, and pollution then it leads to inflammation and swelling. Its important to use heat pack over the lids 1-2x per day and wash the lids with baby shampoo. Omega 3 and good diet is important.

Pimple of lid: This is a blocked eyelid gland which gets inflamed causing local pain, redness and swelling. It is like a pimple on the lid. Treatment is by applying hot washcloths frequently which usually makes it go away. If persistent, see your ophthalmologist.

Clogged oil gland: A sty is when an oil gland of the eyelid margin gets clogged and the oil backs up and forming a pocket of stagnant oil and the eyelid becomes inflamed. A hordeolum is the acute phase or beginning stage of a stye, and a chalazion is the chronic phase (where the oil becomes more granular, thick and the skin inflammation resolves, but there is still a bump/nodule in the eyelid). Warm compresses!