I was wondering whether should I write one common app essay for all colleges or different essay for each college?
Which one would be best? What is normal and usual way people write common app essays?
By definition, you don’t have a choice: the Common App essay is common to all of the colleges/universities who get that application. Where you have a choice is on ‘supplemental’ essays that individual colleges/universities may ask for, and whether you recycle an essay will depend in large part on what the prompts are for the supplemental essays. Most students that I know start with an essay a relatively ‘safe’ school and write that essay first, then use it as source material for the next, saving their favorite schools for last (b/c the essay/essays should get better / stronger as you revise and edit it). Most end up having 2-3 core essays and recycle bits for different apps.
Well, you can change your CA essay for different schools if you want. You may feel, for example, that a school’s supplements cover an aspect that you would have otherwise explored in your CA essay, while another school’s does not. Your choice.
Now you can change the essay before each submission.
Most people do one essay for all colleges. You really aren’t trying to reference the college in the essay anyway – it is about YOU, not about the school. It is your chance to give them a chance to get to know more about you. The only exception my kids made was when a school had a question that really required them to use some of the same content as their common app essay. In that one case, my kid wrote a different common app essay so they could do the best job on the supplemental and use their application “real estate” to their best advantage (not repetitively).