"The children are eating bread."
Translation:Les enfants mangent du pain.
du refers to bread, singularly - des refers to more than one bread. If the sentence was "The children are reading books" then it would be "des livres" instead of "du livre".
why is l'enfants incorrect? isnt l' to be used before a noun that starts with a vowel?
It is, but in this case "enfants" is plural, you must write "les enfats". You use l' when it's only one person L'enfant
l' is used when you have 2 vowels sounds beside each other. that's why l'enfant is correct, but when plural it turns into les enfants, because the s makes it so there are no longer 2 vowel sounds in succession