The syntax of YAML is similar to other high-level languages, and it can simply express data forms such as lists, hash tables, and scalars. It uses whitespace indentation and a large number of appearance-dependent features, and 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 model data structures, there are also sophisticated syntaxes that can express relational model data. Because YAML uses whitespace characters and line breaks to separate data, it is particularly suitable for operations with grep/Python/Perl/Ruby. Its most easy-to-use feature is that it cleverly avoids various closing symbols, such as quotation marks, various brackets, etc. These symbols will become complicated and difficult to identify when the structure is nested.