A programming language allows programmers to develop applications and scripts that computers can execute. Some common programming languages include C, C++, C#, Python, Java, JavaScript, MySQL, PHP, Pascal, R, Fortran, Go, Ruby, and Matlab. JavaScript is especially important as it is the main programming language used to make websites interactive, allowing features like image sliders, dropdown menus, and animated visual effects. Many popular websites use JavaScript, including Google Maps, EBay, Walmart, and LinkedIn. Free online resources like W3School, Khan Academy, and Codecademy can help people learn programming.