Hello Subhransu,
Thank you for reaching out our community. I will try to explain a little this feature.
If you run the Skill mapping process, those selections (and the combination of them) will influence the results - points and percentage.
For your example, if you run the process with "Different from" OFF, Optional OFF, like in your screenshot, then the results will show you the employee
or employees who DO have that Invent skill with a level of 3.
If you check "Different from" to ON, when you execute the process, it will bring you a list of
all employees who DO NOT have this "Invent" skill, of level 3.
If you check Optional ON, it will bring you a list of all employees (cause you told the process that this skill was optional), but in the results the Points and Percentage will be different. The employee with this Invent skill of level 3 will be shown with a percentage of 100%, cause he has it, while the other are listed, but with a percentage of 0. In other words, the other employees do not have the skill, but if the process was supposed to show them, it did, but the fit percentage is zero.
Values get more interesting if you have more skills added. Then there's a calculation based on Skills level and Importance that you set for each.
Will show you a quick test from my environment. I am adding 2 new skills, Test Comm and Test Comm2. Assign them to one employee, with levels of Test comm=3 and Test comm 2=5.

Will set a Skill mapping with both these skills,

and will run process for TestComm to be 5, but highest importance (6 in my case), and TestComm to be also 5, wit low importance.
Since the employee in question has TestComm at level 3, the process is expected to show a low fit percentage.
And here it is , only 14.29

I will switch just the Importance

and re run the process
Now the employee has a higher percentage, cause even though the Skill level of Test Comm is only 3 out of 5, the importance of this is low. As expected, after running the process with the above setup,

I hope my explanation above helps you, please confirm. And if you still have questions, we are here to help.
Best regards,