free is a command that displays used and available memory in your system. Read man page of free command. Run the command free o several times, running other programs in between, and store the results in a file.

Draw a graphs as follows:

X-axis: MB-used;

Y-axis:

1. Memory Used per unit time

2. (Memory Used Memory Buffered Memory Cache) per unit time

3. Swap Used per unit time

Explain the behavior of this graph with respect to memory utilization in the presence of running various applications.