Statement of Purpose (SOP) is a statement about your main purpose of applying to graduate school or university. Because it is a lot of time commitment and it takes away so much of your life and it should be appropriate purpose behind it. So, School and university request students to clarify their main purpose for education like What is the purpose of going to school and university for Graduate program. Your target is to write it up exactly within the length they determine. You should have a target and know how you are going to get to your target and why do you want to get to your goal too. Universities read the SOP seriously so It is very important that you write a good Statement of purpose interlacing your goals, your successes, how will you accomplish your goals and what do you really want to achieve in life, etc.