Well literally, it's " to reach out" , is to stretch out to somebody and we often use it idiomatically to mean to reach out to somebody who needs help or somebody we want to help and give value to.
从字面上来说,to reach out 就是向某人伸手,我们经常用这个习语表示向需帮助人伸手,帮助他人给他人一些价值。
She was within a few steps of it, and Oz was holding out his hands to help her into the basket, when, crack! went the ropes, and the balloon rose into the air without her.