The term "significant difference" refers to a noticeable or important distinction between two things, people, events, or ideas. It implies that there is a notable dissimilarity between them, which sets them apart from one another in a meaningful way. In statistics, the phrase often indicates a difference between groups or variables that is considered to be statistically significant - i.e., it is unlikely to have occurred by chance alone and therefore has practical importance. Essentially, "significant difference" means something that makes a real difference or has an important impact in context.