Conflicts in a story are the struggles that the characters must try to overcome. An internal conflict is when a character must struggle within him/herself, such as making a decision or over-
coming an addiction or weakness. An external conflict occurs when a character struggles against an outside force, such as society, another character, or something in nature.
Three conflicts in this story is Mr. Thompson's internal struggles. First, he feels the need to be respected in his community so he struggles to make a success as a dairy farmer. Second, he struggles with the guilt he feels over killing Mr. Hatch, especially after he's acquitted. Third, he decides to kill himself when he can't take the humiliation of his sons.
There are also external conflicts. Mrs. Thompson, forced to lie at her husband's trial, blames him for ruining their sons' lives and causing Helton's death. Mr. Thompson's sons threaten their father with violence if he frightens their mother again. Then, you have the conflict between Mr. Thompson and Mr. Hatch, which results in the latter's murder.
As you can see, some stories can contain several conflicts. They are the problems of the stories that make them interesting.