The primary use of discernment is to know the difference between truth and error.
We humans have wonderful gifts and talents. We also have the ability to fool ourselves into doing or believing something which is not true or not good for us.
Discernment does involve your intuition. The more you strengthen the skill of intuition, the better will be your discernment.
Discernment also requires the gathering of information. You need to know who to go to or what information to gather to "feed" your discernment in a healthy manner.