Final answer:
A stye is an infection of an eyelash follicle that causes localized symptoms such as pain, swelling, redness, and pus formation at the edge of the eyelid. It is a common condition that usually resolves on its own within a few days.
Step-by-step explanation:
An infection of an eyelash follicle producing an abscess with localized pain, swelling, redness and pus formation at the edge of the eyelid is called a stye. A stye is a common condition caused by the infection of a hair follicle or an oil gland on the eyelid. It usually resolves on its own within a few days, but warm compresses can help alleviate symptoms.