The terms summary and synopsis are frequently used interchangeably. But are there differences between the two?
It seems there is a slight difference and which you decide to write will depend upon who you are sending it to and your ultimate reason for writing one.
A synopsis is a short (and concise) description of a book, while a summary is a lengthier condensed version. While the summary focuses on what happened, the main ideas, and facts, the synopsis is more subjective and reveals the underlying themes, meaning, and so on.
The goal of a synopsis is to help the reader or agent to decide if they want to read the full book. And, in the case of an agent, to determine if they want to pursue representation.
There are times when you’ll be asked to write both of these, so it’s a good idea to look at examples and/or find books which delve into the writing of each.