While both are legal entities, nonprofit corporations, designed to serve and build communities, the Community Land Trust is more narrowly focussed on holding and developing real estate and housing, while Community Development Corporations also work with business, education, and other community issues. The best way to get a sense of the differences would be to compare the several examples you can get to from the sources below.

The Community Land Trust model was developed by the Institute for Community Economics, which maintains a website with information about CLTs including a list of CLTs around the country.

The Wikipedia page on Community Development Corporations links to several examples around the country. There are also histories of several available at the Community Development Corporation Oral History Project from the Pratt Center for Community Development.

The Portland Community Land Trust has a fact sheet (pdf) which compares home ownership under both, though of course it emphasizes the benefits of CLTs!