1. User Experience :- To understand user behavior and their context. Example :- While using online meeting their are three specific actions depends on users situations. to enable or disable using switch. it is easy to take action by the user. 2. Consistent Design :- It help users to recognize and easier to learn the system. Example:- Error message while fill up the sign up form, any important/required field forgot by user will show error message when tap on Submit button. 3. Functionality :- To provide necessary features and functionality related to usage. Example 1 :- Price Range slider to set min and max price range Example 2 :- Provide easy interface to set Travelers & class while booking online ticket 4. Cognition :- Acquiring the Users knowledge and understanding through thought, and their experience, and the senses. Example :- While Join the Swimming class through the app have some important questions to the user. Like how skilled and skilled level. for selecting the skill an