Sometime on Aug 25, rc cobbled together some glyphs to say:

Then monitor the memory usage , you will find that your memory is just utilized without starting any services .

it's not.

run free and see exactly where your memory is being allocated. remember that there's no point having 'free memory'. if your memory is unused, then you bought too much.

linux will use up all available memory for buffers and cache and release that when required by an application.