Ischemia means there is good blood flow to the heart at rest but poor blood flow to the heart at stress (reversible defect). This can be caused by underlying coronary artery narrowing or blockage, placing you at risk for future heart attacks. When you have this, your doctor may decide to intervene by dilating and/or stenting your coronary arteries.
Infarct means there is poor blood flow to the heart during both rest and stress (fixed defect). You probably had a heart attack in the past that resulted in scarred/damaged tissue, which is unfortunate but the damage is already done. In your case, the apex or tip of your heart is now exhibiting dyskinesia, or abnormal movement.
Ejection fraction is a measurement of the percentage of blood pumped out of your heart each time it contracts. Basically it tells your doctor how well your heart is functioning. Your ejection fraction is on the lower limits of normal.
An abnormal result in both phases of your stress test is an indication that your heart's blood flow is poor, regardless of your exertion level. The restricted blood flow suggests significant coronary artery disease.