What is YAML?
YAML is a human-readable data serialization format built around indentation, mappings, sequences, and scalar values. It is frequently used for configuration files, deployment definitions, automation workflows, and structured content.
Why YAML syntax errors happen
Indentation is part of YAML structure, so an extra or missing space can change meaning or make a document invalid. Other common problems include missing spaces after colons, unquoted special characters, malformed lists, duplicate-looking structures, and incorrect block text indentation.
Validation and normalization
Validation confirms that the parser can read the document and reports a line and column when available. Normalized output serializes the parsed data with consistent indentation, which can help inspect structure but does not preserve the original source exactly.
YAML is more expressive than JSON
YAML supports comments, anchors, aliases, tags, multiple scalar styles, and implicit types. Those features are useful, but they also mean valid YAML may not have a lossless or portable JSON equivalent.