What is a pac file and how do I open a pac file?

PAC is a configuration file used by browsers to select an appropriate proxy server. The file contains a JavaScript function named FindProxyForURL that defines rules for choosing a proxy server based on a given URL. It controls and load-balances Internet traffic, PAC files are very vital in corporate environments wherein websites are utilized for business processes as these files have the ability to control and load balance internet traffic that goes into a certain website.  Web browsers enable PAC files when the PAC file URL found in the proxy connection settings is entered. These files can also be enabled by web browsers through the use of the Web Proxy Auto-Discovery (WPAD) protocol. When executed, a PAC file returns a string with one or more proxy server URLs. PAC files are very vital in corporate environments wherein websites are used for business processes as these files have the ability to control and load balance internet traffic that goes into a certain website. PAC files typically are hosted on a web server and are named proxy.pac. PAC files can be edited with a text editor because they contain JavaScript codes.