Code Signing Certificates are used by developers on all platforms to digitally sign the applications and software they distribute over the Internet. Code Signing essentially provides the same assurance as a shrink wrapped CD as the signed code includes the name of the publisher and assurance that the code hasn't been tampered with since being published. Anyone downloading software off of the internet can make a decision whether or not to trust the software.
Code Signing Certificates use a unique cryptographic hash to bind the identity of the publisher to the software. Security warnings that appear with unsigned code are replaced with notifications containing the software publisher's information, preventing users from abandoning the install and increasing download rates. Signing code adds an essential layer of trust to the installation process.
Code Signing proves the signed software is legitimate, comes from a known software vendor, and that the code has not been tampered with since being published. Code Signing prevents users abandoning the installation of an application due to security warning messages, malicious alternation of legitimate code, and identity theft of vendor author.