They serve several purposes in writing:
* Signaling order and sequence: They help the reader follow the flow of your ideas by showing the order in which you're presenting them.
* Adding clarity and coherence: They make your writing more organized and easy to understand.
* Connecting ideas: They show the relationship between different parts of your writing.
These words and phrases are often used in lists, outlines, and instructions to make them more organized and understandable.