Indexing refers to the process of organizing and categorizing information in a way that makes it easier for users to locate, search for, and retrieve specific data. This can involve creating an index or database of keywords and phrases related to the content, which is then used by search engines to help people find what they are looking for on the internet. In addition, indexing can also refer to the practice of assigning numbers or symbols to identify different pieces of information within a larger set of data.