title: Add legend in GNU Plot
body: <p>I have a plot with six different colorline in the same graph in GNU. Now my problem is to give description of the each line in the right side of the graph i.e. I have to add legend. </p>
  
  <p>What command will be useful for this problem?
  Eg: I have to add legend as the figure attached:
  <img src="https://i.stack.imgur.com/NSAxh.png" alt="enter image description here"></p>