The first sentence mean the simple fact.
ex. Chichi ga hon wo kau. / Haha ga hon wo yomimashita. (past)
If you use the second expression (=with "kureru") , it shows that someone do something for me and you're glad for his/her action. It also includes your appreciation for him/her.
ex. Chichi ga hon wo katte kuremasu. / Haha ga hon wo yonde kuremashita.