The regular files in #linux contain data such as text (text files), music, videos (multimedia files) etc. Set aside the regular data, there are some other data about these files, such as their size, ownership, permissions, timestamp etc. This meta-data about a file is managed with a data structure known as an inode.
Resource: https://borosan.gitbook.io/lpic1-exam-guide/1042-maintain-the-integrity-of-filesystems