Backend development involves the programming and management of the 'behind-the-scenes' functionality of websites and web applications. This includes handling website architecture, scripting, and coding to connect the web to a database, as well as developing server-side logic to power websites and apps from behind the scenes. Some common backend languages for development include Ruby, PHP, Java, .Net, and Python, with Python being a popular choice due to its versatility and efficiency. Backend developers require a specific skill set that includes proficiency in programming languages, knowledge of frameworks, and the ability to work with databases. Overall, backend development plays a crucial role in ensuring the functionality and performance of web applications.