It may be the implications of the specifics of my phd topic, which made my eye keener, but I tend to come across the above two terms every now and then. People refer to syntax as to rules and to semantics as to in a way an invariant of those rules and something that one basically wishes to express using the rules.
Today I've bumped into an article with the following title: "Syntax is from Mars while Semantics from Venus! Insights from Spectral Analysis of Distributional Similarity Networks.":
"We observe that while the syntactic network has a hierarchical structure with strong communities and their mixtures, the semantic network has several tightly knit communities along with a large core without any such well-defined community structure."
Another example brought by one functional specification which has found me at work: "The [some company's] command language provides syntax and semantics to perform
service-specific and service-independent management operations."
It is important to notice, that in general one can bind any semantics to a particular syntactic structure, i.e. what exactly happens after applying this particular structure. And at this point we come to another level: pragmatics. What will happen refers to pragmatics behind an action rather than semantics. The semantics is just a formal intermediate representation of used syntactic structures. I will try to gather illustrations in English later.