ArcMap is run using primarily Shape Files and in more recent versions Geodatabases can be used to store larger sets of data. These file formats are what are uploaded into the program to view spatial data.
Edema is swelling of both legs from a buildup of extra fluid. Prolonged standing or sitting, especially in hot weather, can cause excess fluid to accumulate in the feet, ankles and lower legs. Tiny valves inside the veins of the legs can become weakened, causing a common problem called venous insufficiency.
The most common cause of swelling of the legs is oedema, which is excessive accumulation of fluid in the interstitial space; however, any tissue of the legs can be swollen. There are therefore a large number of potential causes.