Wright State University: T.K. Prasad's "Syntax Specification: Grammars"
Read these slides, which will introduce you to syntax as a language. The first few slides provide an overview of compiler, interpreter, and lexical analyzer.
Click http://web.archive.org/web/20141210121836/http://cecs.wright.edu/~tkprasad/courses/cs480/L2Syn.pdf link to open resource.