An Angioplasty refers to a procedure where a catheter is inserted (usually through the groin) and guided to the heart through a vessel that is narrowed. The catheter has a balloon at its tip, which is then inflated and the vessel is dilated up in order to allow more blood flow to get to the cardiac muscle. Heart attacks are caused when a certain part of the heart doesn't receive enough blood flow and the muscle in that area dies from lack of blood flow and oxygen. I recommend consulting with your cardiologist
for further explanations.
Angioplasty procedures are designed to find areas of vessel narrowing (angiogram) and then try to dilate them so that more blood can flow to the heart muscle wall. Sometimes it is not enough to simply dilate the vessel, in which case a stent may be placed across the narrowing to keep it open. Many different types of stents exist and your cardiologist would speak to you and your father about the advantages and disadvantages of the various types of stents. Despite the numberous brands and types, there are two main types (druge eluting and bare metal stents). Consult your cardiologist for which stent is best suited for your father.
In terms of activity levels, he will be limited in the immediate post-procedure time period, however subsequent to this, his ability to be active should only improve after an angioplasty procedure. Please discuss with your cardiologist.