To get a good idea of what paraphrasing tools are, let’s first understand what paraphrasing itself is.

In a nutshell, paraphrasing is the process of changing the words and sentence arrangement(s) in a piece of text to make it look different than what it originally is albeit conveying the same meaning.
Paraphrasing is typically something that a person i.e., a writer or a student, does when the need arises.

Paraphrasing tools, on the other hand, are the modern solution to do the same thing automatically without human effort.

Or, to bring it together somewhat simply, we can say that tools that paraphrase are called paraphrasing tools.
Now let’s talk about how they actually work.

These tools are basically equipped to read the given content and then effect different changes to it. Depending on how high-quality the tool in question is, those changes can be sparse or extensive.

If, for example, the tool is AI-equipped, it will understand the given content very deeply, and it will likewise make changes to it smartly. But if it is just a normal simple tool, it will merely skim the surface, so to speak.