A virtual private network is a way of connecting to the internet in a more secure or private way, by sending your data through an encrypted tunnel and hiding your true IP address -- making it harder for someone to track your online activity.
In a business environment, VPNs are often used by employees who are working remotely and need to access their company's intranet securely. Beyond that, most VPNs are used for one or more of the following purposes: to bypass internet censorship in countries without free speech; to bypass geography-based restrictions on streaming services like Netflix; to secure privacy while using peer-to-peer networks for torrenting; to hide internet activity from local network moderators such as those on a college campus; or to securely transmit user login credentials on public Wi-Fi when using outdated apps or operating systems.
When deciding on a new VPN service, the following terms can help you navigate the field and understand what a provider offers. Read the entire article, All the VPN terms you need to know, on CNET.