1. You can program the ROBOTS and Automatic Running Machines using C language. click here for more information. 2. For building more advanced software or Games you need to learn more advanced languages like Visual Basic, .NET, JAVA, ANDROID programming which is based on C. 3. To build a website you need only HTML and you can make your own website but for making it more advance you need to learn more web designing languages like CSS, JavaScript, Ajax, PHP and this all languages are very easy to learn if you have some basic knowledge about C. 4. After learning C you will be able to make your own software like Calculator, Games, Embedded Softwares, Compilers.