Cohesive devices are linguistic elements like pronouns, conjunctions, and lexical reiteration that link different parts of text together at the semantic level. The major functions of cohesion are to create a unified text and help the reader comprehend relationships between sentences and paragraphs. There are various types of cohesive devices including reference, substitution, ellipsis, conjunctions, and lexical items. Proper use of cohesive devices improves readability and makes a text more cohesive and meaningful.