A degree with a foundation year can be an alternative to an Access course. Completing a foundation year may offer direct entry to the degree course and be eligible for student finance. A foundation year can be used by someone with the wrong subject level 3 qualification, very low level 3 passes or a mature student with relevant work/life experience. The entry criteria will vary from course to course.
A foundation degree is a 2 year course, it may have lower level 3 requirements than a full degree. It is actually more like a HND. You can study for a further year to complete the fully honours degree.
Unfortunately the naming structure can lead to confusion and misunderstanding.