When you write sentences in a paragraph, it is important that they connect logically with each other. For example, the following group of sentences connects well. The sentences follow each other logically.
But in the next example the sentences do not connect well.
The problem with Paragraph 2 is that the sentences do not connect well. It is hard to understand the meaning of the paragraph. The order of the sentences is wrong. Paragraph 1 is a better paragraph.
In the next example, the sentences are in the correct order, but they do not connect well. There are no sequence markers to connect the sentences. Also, we do not really know what the main idea is.
Look at Paragraph 4 and see how Paragraph 3 has been improved. We have added sequence markers to connect the sentences. We have also added another sentence at the beginning that tells us what the main idea is.
The sentences in this paragraph are in the correct order, and there are sequence markers connecting the sentences in a logical way.