Usability refers to the ease of use and learnability of a product or system. It measures how well users can complete tasks and achieve their goals efficiently and effectively. A usable product is one that is intuitive, simple, and user-friendly, allowing users to interact with it seamlessly.
Usability testing is a method of evaluating a product's usability by observing users as they perform tasks with the product. The goal is to identify any usability issues and improve the product's design. Usability testing can be conducted in-person or remotely and can involve both qualitative and quantitative data collection methods.
User-centered design is an approach to product design that prioritizes the needs and preferences of the end-users. It involves understanding user behavior, preferences, and pain points through research and feedback, and incorporating this information into the design process. User-centered design aims to create products that are intuitive, easy to use, and meet users' needs.
Accessibility refers to the extent to which a product can be used by people with disabilities. An accessible product is one that can be used by everyone, regardless of their abilities. Accessibility considerations include visual, auditory, and motor impairments, and can involve features such as alternative text for images, closed captions for videos, and keyboard navigation.
User Interface (UI):
The user interface (UI) is the visual and interactive part of a product that users interact with. It includes elements such as buttons, menus, icons, and text, and is designed to be intuitive and easy to use. A well-designed UI can enhance usability by making it easier for users to complete tasks and achieve their goals.