Difficult is the opposite of easy. It means that something requires lots of effort to do it. Hard can be the opposite of "soft" (such as a hard pillow and a soft pillow) but it can also mean "difficult."
For example, you can say:
The test was difficult. = The test was hard.
It's difficult to understand the teacher. = It's hard to understand the teacher.
The word hard is a little more informal, so it's better to use difficult in more formal writing.
The word hard can also be an adverb to describe doing an action with great effort or energy. We often use it with the verbs work and try:
No mess, no carve These lanterns are the perfect almost pumpkin. Cut out smiling jack o lantern faces from black cardstock; tape to orange cardstock cut to fit the lantern panels. Use indoors or in a protected outdoor space.
Editors Tip Make this decoration last longer by placing cardstock behind the lanterns glass panels.