What words is an indefinite article?

An indefinite article is a Word that introduces a noun without specifying which one, typically used to refer to a general item rather than a specific one. In English, the indefinite articles are "a" and "an." "A" is used before Words that begin with a consonant sound, while "an" is used before Words that start with a vowel sound. For example, "a cat" and "an Apple" both refer to any cat or Apple, not a particular one.