From my good friend Oxford

I thought I'd just throw this out there; a bit of grammar to go with Molly's faux amis sexuelles. If you want to be a language professional and don't understand some terms below, like 'restrictive relative clause', let me know and I will very happily keep posting this stuff. Very happily. And who knew doc Ox "hmph'd"?

Is there any difference between the use of that and which ?

Is this:
'Any book that gets children reading is worth having.'
the same as this?
'Any book which gets children reading is worth having.'

The general rule in British English is that, in restrictive relative clauses, where the relative clause serves to define or restrict the reference to the particular one described, which can replace that. However, in non-restrictive relative clauses, where the relative clause serves only to give additional information, that cannot be used: this book, which is set in the last century, is very popular with teenagers.
but not
this book, that is set in the last century, is very popular with teenagers.

In US English which is generally used only for non-restrictive relative clauses.
Hmph.