Ihsan is the highest level of Iman. The meaning of Ihsan as it came in Jibril’s hadith is “It is that you should serve Allah as though you could see Him, for though you cannot see Him yet He sees you.”
This meaning has two stages, the first stage is to serve Allah as if you are seeing Him, when you feel that you are seeing Allah, definitely you will serve him with excellence.
If you can’t achieve the first stage move to the second stage which is to be certain that Allah sees you. And that He is All-aware of your actions and deeds.
Ihsan has another meaning which is perfection or excellence.
Once you are aware of Allah’s awareness, you will try your best to achieve perfection in all your actions, worshiping, and even your attitude towards people.
This meaning is described in the hadith:” Allah has prescribed “Al Ihsan” in every matter.” And also in the hadith:” Allah loves that when one of you accomplishes a work, that he accomplish it with excellence”.
The first hadith shows us that Ihsan is not only a level of Iman but it is also a way of life. And in the second hadith Allah asks us to accomplish all our activities with excellence, and this is Ihsan.
Ihsan means trying your best to obtain perfection in each and every perspective in life. And this definition includes the first definition in a way, that if you do all your activities with excellence you will do your worshiping with excellence.
The first definition includes the second one as you can’t achieve excellence in everything, unless you feel that you are seeing Allah every second, or at least you are certain that He sees you all time.