Syntax specifies the required combination and sequence of characters making up correctly structured code. Syntax generally includes grammar and the rules that apply to writing it, such as indentation requirements in Python.
Syntax applies both to programming languages (commands to the computer) and markup languages (document structure information) alike.
Syntax only governs ordering and structure; the instructions must also be meaningful, which is the province of semantics.
Frameworks are said to have a "clean" syntax if they produce simple, readable, concise results. If a codebase uses "a lot of syntax", it requires more characters to achieve the same functionality.
- Syntax (programming languages) on Wikipedia