Ambiguity refers to words, phrases, or sentences that have more than one possible meaning or interpretation. There are two main types of ambiguity: structural ambiguity, which occurs when a sentence's structure allows for multiple interpretations despite clear individual words, and lexical ambiguity, where a single word can have multiple meanings depending on context. Examples of structurally ambiguous sentences include "Raimi bumped into a man with an umbrella", which could mean either Raimi or the man had the umbrella. Lexical ambiguity is exemplified by the word "young" meaning either a young age or lack of experience, and "bank" referring to the side of a river or a financial institution.