HELP OUT is a phrase that means to assist or aid (someone), esp. by sharing the burden. e.g. Everyone helped out during the flood It has the same meaning as help but is more similar to assist in the sense that we share the burden of the work.

"Help out" simply means to help somebody do something, either by effort or giving money. In many cases, you could just use help. "I helped him fix his car." "He was fixing his car and I helped out." "He helped me with my income tax when I was having trouble." "He helped me out with my income tax when I was having trouble."