that's right:没错,对.表示同意.
如:
Mom:Today is friday,right?
Me:That's right.
如:that's all right:没关系.表示谅解,不用谢.
Someone:Oh,i m sorry.My apologize.
Me:That's all right.
that is right没错,对(表示赞同前面那个人说的话)
that is all right没关系,不客气(常用做thank you 的答语)
希望能够帮助到你哦。
前者是没关系,后者是 那是对的。