The sign is anything that stands for something other than itself. A sign is a piece of information that is composed of 2-3 parts. Two parts are the signified and the signifier. The signifier is the sign itself, the signified is the concept or thing that the sign is representing. The third part are the people using the sign.
There are three types of signs: icon, index and symbol. An icon physically resembles the object or concept it is intending to communicate. In language onomatopoeic words are considered icons. An index is a step removed from an icon, but there is still a direct link between the sign and the object, such as smoke representing a fire. A symbol is a learned meaning that is agreed upon and used by cultures.
A syntagm is a collection of signs that are organized in a linear sequence to create an intended meaning, such as a word or sentence.
A paradigm is a set of signs that when combined and re-arranged create new meanings, such as the alphabet. The alphabet is also a code because it has a fixed number of signs, which is a digital code. There are also analogue codes, which are a paradigm with infinite choices such as brush strokes or
A polysemy is a type of sign with multiple meanings and depends on the context in which it is used for the audience to understand. For example the word crane, it is a bird, or a constuction machiene, or a verb for movment, ( I craned my neck).