Grep is a command-line utility used in Unix and Linux operating systems for searching plain-text data sets for lines that match a specified pattern. The name stands for "global regular expression print," reflecting its ability to search using regular expressions, which are sequences of characters that define search patterns. Users can employ grep to filter text files, making it easier to find specific information quickly. It can be used in various contexts, such as programming, data analysis, and system administration, enhancing productivity by allowing users to locate relevant data efficiently.