Some definitions

I wander a lot, I know, but this blog is intended to be about languages and related topics.
As I already said, I am writing here only to keep track of what I read in the net. So, to clear my mind a little, I think I should start with some definitions.

What is language?
A language is a system, used to communicate, comprised of a set of symbols or sounds and a set of rules (or grammar) by which the manipulation of these symbols is governed. These symbols can be combined productively to convey new information, distinguishing languages from other forms of communication.

What is dialect?
A dialect (from the Greek word διάλεκτος) is a variety of a language used by people from a particular geographic area.

What is vocabulary?
A vocabulary is a set of words known to a person or other entity, or that are part of a specific language.

What is grammar? (Maybe I should also ask why so many spell it "grammer")
Grammar is the study of rules governing the use of language.

What is linguistics?
Linguistics is the scientific study of language.

What is syntax?
Syntax (from the Greek words συν, meaning "co-" or "together", and τάξις, meaning "sequence, order, or arrangement") is the study of the rules, or "patterned relations", that govern the way words combine to form phrases and phrases combine to form sentences.