Which Linux/Unix command is used to search for a specific pattern of text within one or more files?

grep (Global Regular Expression Print) searches the contents of one or more files for lines matching a specified text pattern (which can be a plain string or a regular expression) and prints the matching lines. find searches the filesystem for files based on criteria like name, size, or modification time (not file contents), locate searches a prebuilt filename database, cat simply displays file contents without searching, and awk is a more general text-processing language that can search but is typically used for more complex field-based data manipulation.