“We really appreciate all of your hard work and effort.”
You are the director of a division in your company. Last quarter, your company had high sales growth. Now you are leading a meeting and you say this to thank all the employees.
We really appreciate all of your hard work and effort.
When you "appreciate" something, it means that you notice it and are thankful for it.
You say "I appreciate ___" or "We appreciate ___" when you want to thank someone for their actions. This phrase sounds more clear and explicit than just saying "Thank you for ___".
An example of this is when your child confesses that she broke something, and you say:
I appreciate your honesty.
"Hard work" and "effort" are very similar in meaning, but we often use them together anyway. They're usually said or written in this order, not as "effort and hard work".