+0
Could someone tell me if these sentences are correct, and what is the difference between.

Did you eat bread.

Have you eaten bread.

They went to France during the holiday.

They have been to France during the holiday.
+1
1. Simple Past Did you eat bread?
2. Present Perfect. Have you eaten bread?

The first one is disconnected from the present. You are asking what happened in the past. There is no limit to how far in the past the bread eating occurred. You can add a phrase that says when the bread eating occurred: Did you eat bread last week?

The second one is connected to the present. It asks how things are now as a result of your experiences in the past. It asks if you have (now) the experience of bread eating. You cannot add a phrase that says when the bread eating occurred. Have you eaten bread last week?

CJ
Comments  
a) Did you eat bread? (Interrogative Sentence)

It describes an action which happened in a clear time,and the time period has finished.

Have you eaten bread yet? (Interrogative Sentence)

It describes an action which happened in an unidentified time,and the time period hasn't finished.

b) They went to France during the holiday. (Affirmative Sentence)

It is used to talk about an action with adverb during ,the action have finish already (They aren't in France now).

They have gone to France during the holiday.(Affirmative Sentence)

Or: They have been in France during the holiday.

It is used to talk about an action with adverb during,the action haven't finished yet ( They are still in France).

It's just my opinion,you can search more.
 CalifJim's reply was promoted to an answer.