Good design should take into account the physical abilities and limitations of users.

The relationship between controls and their effects should be intuitive and consistent.

example: pro

The controls on a toaster typically include a lever to lower the bread into the toaster, a dial or buttons to set the desired level of toasting, and a button or le...

Users should be informed of the results of their actions and the system's current state.

Making use of constraints guides the user in the roght direction

example:

ATM may be designed to only allow the user to make a withdrawal after they have inserted their bank card and entered their PIN (Personal Identification Number). This constraint guides the u...

Break down complex tasks into smaller, more manageable sub-tasks.

example:

contact form in a website, by breaking down the task into smaller sub-tasks such as filling out personal information, the subject, and the message, the user doesn't feel overwhelmed and c...

Provide a good starting point for users and make it easy to return to a known state.

example:

"The Nothing Phone 1 was so similar to the Apple iPhone that it immediately had a positive influence in the smartphone market."

Allow users to adapt the system to their needs and preferences

example:

A thermostat with a digital interface, where the temperature, fan speed, schedule and other options are easy to find and adjust.