Final answer:
A stye is a localized, circumscribed inflammatory swelling caused by an infection of a sebaceous gland in the eyelid. It appears as a red, tender bump and is usually treated with warm compresses and antibiotics if necessary.
Step-by-step explanation:
Localized Inflammatory Swelling of a Sebaceous Gland of the Eyelid (Stye)
A stye, also known as a hordeolum, is a localized, circumscribed inflammatory swelling that occurs due to the infection of a sebaceous gland of the eyelid. Styes are typically painful and appear as red, tender bumps near the edge of the eyelid. They occur when bacteria enter and infect the oil glands in the eyelids. Treatment for a stye often involves warm compresses and antibiotics if necessary. It is important not to squeeze or pop a stye as it can lead to further infection or complications.