There are many reasons obviously will affect what communities you are in. Races, cultures, and careers, all of these will cause what kind of group people in. However, I think that there is a very basic reason for delineating boundaries between communities, which is education. People have different educations will absolutely decide to join in different communities. With distinctive level of education, people will have dissimilar academic level, experience, and friends. Those things are the most part of your life.
With unique academic levels, people have their own perspectives to this world. What they understand the world bases on the things that they learn from outside. When I was in primary school, I just knew a little about this world. I did not understand why I could not touch stars in the sky, though I really wanted to because they were so beautiful. I loved cloud, which suspended in the sky and I even imaged to take airplane to stay around clouds. As I came to high school, I knew that clouds were in the thousands of meters high above ground, and it is uneasy to feel it. Also, in my chemistry class, I learnt that cloud is another phase of water, so I created my own cloud in my room. Now, I go to college so that I could learn more about our world, and my view of this world will keep changing in the future. Same as what I do, people will also keep changing their opinions to this world even something keep same; indeed, our world are changing every single second. This is one factor of education delineating boundaries between communities.
Another reason for it is experience. When people slowly grow up, we experience many unpredictable things. We always meet many unbelievable surprises; some are bad, while others are wonderful. Whether you like it or not, you need to face it and solve it. Life likes a game, but you will never repeat any moment just totally different from what you do in computer game. If you make a great decision, you may have a good time; otherwise, you need to be tough until finding a chance to change your situation. From this process, you will learn to face everything in your life with a positive side. It will help you get into different communities.
The last part is friends, who influent your behaviors, emotions, and characters. In the different parts of life, you meet lots of people; some are your friends who impact your entire life, others are just some strangers passing by. A sage ever said, “ If you want to know a man, you just need see the friends around him.” Friends around you will tell everybody else many characters about yourself. After leaving school, you will also have a stable group people including your co-workers, relations, and your friends. Those people decide your community, and determine what kind of people you live with.
From all above, we could see how important your education relates to the community. Education not only indicates what community you should join in, but also is an essential factor of your entire life. This is the factor that I think delineate the boundaries between communities.