Heart failure is the condition in which the heart is unable to perform the work necessary to keep up with the body's needs. In most cases, heart failure is accompanied by significant fluid accumulation, which tends to cause fluid buildup in the lungs (leading to the shortness of breath that occurs with heart failure), and swelling (edema) in the feet and legs.
The term "congestive" heart failure refers to the fluid buildup in the lungs -- that is, to lung congestion. Since this lung congestion occurs to some extent in the large majority of patients with heart failure, most people with heart failure can be said to have congestive heart failure. This is why "heart failure" and "congestive heart failure" are considered virtual synonyms by most doctors.
Rare patients with heart failure may have little or no lung congestion. In these patients, the main problem tends to be the extremely weak heart muscle's inability to pump enough blood to the body's organs, leading to dangerously low blood pressure, and extreme weakness and fatigue. These patients are sometimes said to have "low output" heart failure instead of congestive heart failure.
But for the most part, the terms "heart failure" and "congestive heart failure" refer to the same condition, so in your case, your doctors are both saying the same thing about your cardiac condition.
Mosterd A, Deckers JW, Hoes AW, et al. Classification of heart failure in population based research: an assessment of six heart failure scores. Eur J Epidemiol 1997; 13:491.