AbpMon usually shows animated icon in System Tray. System Tray also called "taskbar's status area" by Microsoft. You can select few variants of icon and information it shows. See Tray Icon Settings for more information. Information includes Graph of CPU Usage during last few refresh intervals, Random Access Memory (RAM) usage, Swap File usage.
Left button mouse click shows or hides AbpMon window. Right button mouse click shows AbpMon Menu..