SRT (SubRip Text) subtitle files are plain-text files that contain subtitle information, including the start and end time codes for each subtitle text segment, and the actual subtitle text itself. These files are widely used for adding synchronised subtitles or captions to videos, making them more accessible to audiences with different language preferences or hearing impairments. SRT files can be edited using basic text editors or specialised subtitle editing tools, and they are supported by most video players and video editing software.