Web development can be defined as the process of creating and maintaining websites. It involves different tasks such as designing, coding, and optimizing websites for better user experience and search engine ranking. Web developers use various languages like HTML, CSS, JavaScript, PHP, and others to develop websites that meet the requirements of the client and the end-user.

Web development has three main layers, which include:

1. Client-side scripting: This layer handles the interactive parts of a website, which include user interface and user experience. Mainly, this covers the website’s interface design, which includes HTML, CSS, and JavaScript.

2. Server-side scripting: This layer cultivates and manages database and server application engines. This covers website’s functionalities that happen beyond the surface-level interactions, which includes PHP, ASP, Python, and Ruby.

3. Database technology: This layer stores and manages data on a website, which includes MySQL, Oracle, and SQL Server.

Web development is a complicated and diverse field that involves various specialties. Apart from the three layers, web developers may specialize in areas such as:

1. Front-end development: This is the development of the visible part of a website that the user sees and interacts with. It involves programming languages like HTML, CSS, and JavaScript.

2. Back-end development: This is the development of the background processes that happen behind the scenes, such as the saving of data, the organization of databases, and more. Most often, front-end developers pair back-end developers to create working web applications.

3. Full-stack development: This is a combination of front-end and back-end development.

Web development has become an important aspect of any business that operates both offline and online. It can help establish credibility and attract potential customers with an easy-to-find online presence. It can also help businesses manage customer databases, online payments, and more.