他过来了。（you can see the process.） 过来： 强调过程 他来了。（he is now in front of you.） 来：强调结果

来 is mean come. 过来 is mean come here. For example 1.Please come to my house. means “请来我家” 2.Please come here. means “请过来” “过来” is used to ask someone to walk to your side. Hope it can help you