Difference between ODBC and OLE DB data sources

In this post I want to explain the difference between ODBC and OLE DB.This is what I found based on my reading on the web and my understanding.

1) ODBC provides access only to relational databases

2) OLE DB provides the following features:

a) Access to data regardless of its format or location

b) Full access to ODBC data sources and ODBC drivers

In simple words, ODBC is used only for SQL based data sources whereas OLE DB is used for both SQL and non SQL data sources.I have put in a diagram also below. That might explain it better.