how to merge text with an image

Perhaps Im using a program too advanced for such a simple task. I simply want to add a line of text on an image and then save it on there so it is permanently attached on the image...i.e if I move the image over, the text will move with it and stay in the same position so I dont have to spend another hour realigning it perfectly

Mail merge? So many possible interpretations...

Can you show what you are trying to do?

What do you want to achieve? That an image has the shape of the text?

The keyword would be "Clipping mask". Exists in Photoshop as well and wouldn't cause any flattening at all.

Place the text on a separate layer, which is what happens automatically when selecting the Text Tool,  then to combine Flatten the document.

Sorry if this isn't the same in Illustrator as in Photoshop but that is how it works in PS.