Security for protecting your applications and data can be implemented in various ways.

For desktop applications, you can simply use the windows security for protecting the entire computer. However custom security can be built directly into an application to provide varying levels of access based on the user who is logged into the computer or the user logged into the application.

For web applications, you can use windows security for protecting the entire website, or custom security programmed directly into the web-based application. Web-based applications can be deployed to a local intranet instead of the public Internet.

For remote offices, there are various technologies you can use to link to private web sites on internal servers, and private databases for desktop applications. A common technology is a VPN (Virtual Private Network) router by companies like Linksys. This device creates an encrypted path between a remote location and a central location across a public network like the Internet. This keeps your central location secure and enables remote locations to operate as if they were connected directly to the central location.