They are almost the same meaning ,to assist ,aid or give a hand,however 'to help out' is associated specificallly with helping by sharing the burden with another person.

There is no big difference if you say either one. Help out is common as a phrasal verb for daily use. Ex: why didn´t you tell me you had problems with Math? I could have helped you. Or Why didn´t you tell me you had problems with Math? I could have helped you out. Help out: expression "give you a hand" = Help :)