This rough-draft paragraph<em> lacks introduction and it jumps from one idea to another immediately, without properly connecting these two.</em>
An introduction is designed to grab the reader's attention and give them an idea about the focus of the essay/paragraph. An introduction often contains a thesis sentence which a claim.
After the introduction, body paragraphs follow. Each one should begin with a topic sentence. Each body paragraph should also have a closure.
Jumping from one body paragraph to another is not a good idea as it confuses the reader and focuses his attention on the next topic, without having thought properly on the first one. Therefore, it is always better to connect two separate body paragraphs with at least one overlapping line. It can be a common idea appearing in both paragraphs, a writer's suggestion or a statement referring to both. This way, the fluency of the writing is guaranteed.
Finally, every written work should end with a conclusion that summarizes the author's ideas and leaves the readers with something to think about.
