Infarction is tissue death (necrosis), caused by a local lack of oxygen, due to an obstruction of the tissue's blood supply. The resulting lesion is referred to as an infarct (from Latin "infarctus" meaning "stuffed into".
Depending on the amount of blood present:
White infarction (anemic infarcts), affect solid organs, e.g. spleen, heart, and kidneys, wherein the solidity of the tissue substantially limits the amount of nutrients (blood, oxygen, glucose, fuel), that can flow into the area of ischemic necrosis. Similar occlusion to blood flow and consequent necrosis can occur as a result of severe vasoconstriction as illustrated in Raynaud's phenomenon, that can lead to irreversible gangrene
Red infarction (hemorrhagic infarcts), generally affects the lungs or other loose organs (testis, ovary, small intestines). The occlusion consists more of RBC's and fibrin srands