Cohesion and cohesive ties
The difference of the presence or absence of cohesion for a text is illustrated in the following examples:
(1) To reach the movie theater you will need to turn right on the next intersection and then go straight for about 5 minutes. You will see it on your right-hand side.
(2) A cat catches a mouse. The car broke down. I go swimming
While the set of sentences in (1) seems to make sense, i.e. we could easily find the movie theater if we were in the given situation, the set of sentences in (2) does not qualify as unified text, but simply as three completely unrelated sentences. There is no possibility to relate the three sentences in (2) to each other, not even by changing their position.