Lexical cohesion is the characteristic continuity of semantic mean of text.
Lexical cohesion is a direct result of a body of writing “being about the same thing.”
For example, a group of sentences in a paragraph are not random and disconnected. Rather, they coherently “stick together.”
The study of cohesion, lexical or otherwise, is quite possibly the most important component of linguistics.
There are two main types of cohesive relationships, reiteration and collocation, and Halliday and Hasan go further to classify cohesion into five categories based on specific word dependency relationship.
Reiteration and collocation can be described in effectively simpler terms.
Reiteration involves the repetition of lexical items across sentences.