This morning in a discussion on this topic on the OSGeo Incubator mailing list, Frank Warmerdam explained the difference between the two terms and now I better understand why the terms Intellectual Property and Copyright should not be confused, especially in the context of Free and Open Source Software (FOSS).
I thought I'd share a copy of Frank's great explanation here in case it helps others better understand the distinction:
I believe the rationale behind avoiding the term Intellectual Property
has two parts.
First, it attempts to conflate a variety of very different legal mechanisms.
Primarily copyright, patents and trademarks. Giving them all one name makes
it harder to separate out things we might agree with (copyright) from things
we might not (ie. Patents).
Second, it expresses these legal mechanisms in a manner that implies that
they are some sort of fundamental or manifest right rather than limited
government granted monopolies intended to serve specific needs of society
[...]You can read the full email and the rest of the thread here.