Difference between 而, 但 and 和
When you use 而, you are always expressing some kind of adversative meaning weaker than 但. Most of the time they can substitute each other but not 100% certain.

Example 1:  both are fine   


  这件事很难，而那件事很容易。 => This thing is difficult while that one is easy.
  这件事很难，但那件事很容易。 => This thing is difficult but that one is easy.


Example 2: 而 is better here  


  他没有出国，而是留在了国内。 => He stayed in home country instead of going abroad.  


Example 3: 但 is better  


  这杯水不甜，但富含营养。 => This cup of water is not sweet but full of nutrition.


The differencies are subtle, taste them in more practice.



It's clearer to distinguish 而 from 和. Remember 和 has no adversative meaning, and in most cases it connects objects:


  Tom and Jerry are good friends.
  Correct: 汤姆和杰瑞是好朋友。
  Wrong: 汤姆而杰瑞是好朋友。