Web development can be a pretty broad term when it comes to building websites! One way to think about it is to compare it to running a restaurant.
Just as a restaurant needs a physical space, menu, and staff to serve customers, a website needs a domain, design, and code to provide information and functionality to users.
The "front-end" of web development, involves designing the layout and user interface of the website, just like how a restaurant design the physical space that customers will interact with. In a restaurant, this can include things like the layout of the tables, the menu board, and the decor. On a website, this includes things like the template, images, UX, and design.
The "back-end" of web development involves creating and managing the functionality of the website, similar to the kitchen and staff of a restaurant. In a restaurant, the staff manages all the tasks hidden to customers like maintaining cleanliness, cooking the food, and settling checks. On a website, the code, database, and software components do the behind the scenes work to make sure all the elements of the website work: forms are sent, orders are processed, pages load quickly, etc.
Just like a restaurant needs both inviting space and competent staff to deliver a great dining experience, a website needs both front-end and back-end development in order to function properly, allow visitors to find the information and features that they need, and provide a great user experience.