Difference between 100 and 101 matches
Context: You wonder whats the differences between 100% and 101% matches.
The difference between the 100% matches and the 101% matches is the context. We also call the 101% "context matches".
A context match is a 100% match withing the same context (previous and following segments are the same as what is stored in the TM for this match).
A source text may very well have several very valid 100% matches, yet 101% matches are unique, as they do take context into account.
Let's say that in your original document, you have a head title called "Setup". Let's also assume that this "setup" was the same term used for two different meanings, the first one "installation" and the second one "configuration" later on in the document.
Without context, you would be at best offered two 100% matches, up to you to choose which one should be used.
With context matching, you will get exactly what is needed, 'installation" as 101% match in the first occurrence and "configuration" later on in your document.