Hundred
Definition 1 of 4
Pro Tip 1/3
Round Numbers
Hundred is often used to estimate or round numbers for simplicity. There were roughly a hundred people at the event.
Pro Tip 2/3
Not Always Exact
'Hundred' can be used to imply many, without meaning the exact number. I have hundreds of photos in my album.
Pro Tip 3/3
Idiomatic Expressions
'Hundred' is used in expressions like 'give it one hundred percent', meaning all-out effort. You need to give it one hundred percent to succeed.