A servant loves his master and enjoys his role of serving but he is not privy to his lord's personal life and his doings. For example, a servant's role is to serve and not become personally acquainted with the one he is serving. He goes when the master says go and comes when the master says come. You see the master will spend time but he tells the servant what to do. The other things the servant does is because he is loyal and does the things he has already been commanded to do. We choose to be servants of the master. For as a man thinketh in his heart so is he and out of the abundance of the heart the mouth speaketh. (something to think about).
A friend on the other hand will know the servant's master as his friend. Their relationship will be on a higher level. They will spend time together say golfing, dining, traveling or just sitting talking to one another about their hopes and dreams and business deals. The friend asking the other for advise on sensitive issues knowing he can fully trust him. The master would not speak to a servant like this. The friend will come and go and each time the friend comes they will spend time communing and enjoying each other's company. There will be laughter and joy and gladness and maybe a few tears when the friend comes to visit. The friends will have a deeper love for each other. The friend longs for the arrival of the servant's master insomuch as to cry out when he arrives, because he has been watching and waiting for him.
Here are some scriptures to take a look at in (Jn. 15:13-15) Jesus says that: Greater love hath no man than this, that a man lay down his life for his friends. (14) You are my friend IF you do whatsoever I command you. (15) Henceforth I call you not servants; for the servant knoweth not what his lord doeth: but I have called you friends; for all things that I have heard of my Father I have made known unto you.