Delete HTML Elements

I can not understand the different meaning between “delete and leave” . I made my challenge good. but by misunderstanding I can not hold my performance. If I am wrong to say, forgive me as I am a new for this tutorial and I am Bangladeshi. For this reason I can not understand the meaning of the words.
But I deleted the whole elements of the tutorial.(deleting element)

To delete is to remove the element. To leave something means to not touch it and to not delete it.

You may want to use Google Translate if you’re confused about instructions.

I will try and thank you for the help.