Cohesion refers to linking words, sentences, and ideas together in a text. There are three main ways cohesion is created: 1) Connectors are joining words like "although" and "in spite of" that link ideas and indicate functions like contrasting. 2) Reference words like "who", "which", and "this" refer back to people, things, and ideas already mentioned to avoid repetition. 3) Referring to other parts of a text, using expressions like "as follows" and "see above", makes lengthy texts more comprehensible by connecting different sections.