YAML syntax is similar to other high-level languages, and can simply express data forms such as lists, hash tables, scalars, etc. It uses whitespace indentation and a lot of appearance-dependent features, which is particularly suitable for expressing or editing data structures, various configuration files, dumping debugging content, and file outlines (for example, many email header formats are very close to YAML). Although it is more suitable for expressing hierarchical data structures, there is also a sophisticated syntax for expressing relational data. Because YAML uses whitespace characters and line breaks to separate data, it is particularly suitable for grep/Python/Perl/Ruby operations. Its most easy-to-use feature is to cleverly avoid various enclosing symbols, such as quotes, various brackets, etc., which become complicated and difficult to recognize when nested structures.