The verbs くれる、あげる、and もらう descirbe transactions of things. When these verbs follow the te-form fo a verb, they describ the giving and receiving of services.
te-form + あげる: I do something for you, you do something for others, I do something for others, somebody does something for somebody else
te-form + くれる: Somebody does something for me, you do something for me, somebody does something for you
We use the te-form + あげる when we do something for the sake of others, or somebody does something for somebody else. The addition of the helping verb あげる does not change the basic meaning of the sentences, but puts focus on the fact that the actions were performed "on demand" or "as a favor"
We use くれる when somebody does something for us.
We use the te-form + もらう to say that we get, persuade or arrange for somebody to do something for us.