In the context of web hosting, a "vhost" is an abbreviation for "virtual host." A virtual host is a method of hosting multiple websites or domain names on a single web server. 

Virtual hosts are commonly used in shared hosting environments, where multiple clients share a single server. Each client is assigned a virtual host, and they can manage their website independently without interfering with other clients' websites. 

Virtual hosting is achieved through the use of HTTP server software, such as Apache or Nginx, which can handle multiple domain names and route incoming requests to the appropriate virtual host based on the domain name or IP address associated with the request