Relationship with God vs Fellowship with God, are they synonymous?

Are these synonymous? My question is based on the point of already being a Christian. I’m open to any ideas and eager to hear them. Please note, I’m not looking for definitions of these terms. I’ve read many from various sources, and they are so minute that it renders them nearly identical. I am asking if the idea of relationship and fellowship (with God) is the same? If not, what are the differences? Does exegesis of biblical ideas exists, and if so what is the term for it? Of course any Bible verses that detail the differences in meaning of these ideas would be extremely helpful. I don’t know enough about Greek to figure that out on my own. I’m not asking out of mere curiosity, I’m studying to learn about these things for my personal growth.