People that are well informed know that bordeaux is a french

Got this sentence on the web which fits in our context nicely:

The store honored the complaints that were less than 60 days old.
This sentence means that the store honored only those complaints which were less than 60 days old and did not honor complaints which were more than 60 days old. Thus we have a restriction on the complaints addressed by the store, as put by the restrictive clause 'that were less than 60 days old'.

Now, let's look at a non-restrictive clause example.
The store honored the complaints, which were less than 60 days old.
Though this sentence looks similar to the one above, it has a different meaning. This sentence makes use of the non-restrictive clause 'which were less than 60 days old' to state that the store honored all complaints and the complaints it addressed were all less than 60 days old. This means that although the store expected complaints both less than or more than 60 days old, it did receive only complaints which were less than 60 days old. Thus the clause does not add more meaning to the sentence 'The store honored the complaints' and hence is non-restrictive.

Hope this cleared your doubt. If not, do let me know!

Cheers!

That was very helpful Sudish. Thanks :-D