google_ad_section_start is a keyword that the Google Adsense service uses to focus on a page section. Or, more precisely, a webmaster of a web uses this keyword in the HTML code to emphasize a page section that he wants the Google crawlers to see and pay more attention to. This is called Google Ad Section.
Browser Safe Colors is a term that refers to the array of colors that can be described in the computer language using only 8 bits.
In the days when 8-bit monitors were the standard, a web developer had to restrict himself or herself to only the browser safe colors in order to ensure that the colors he or she chose would appear correctly on web pages.
The Microsoft .NET Framework is a software component that can be added to or is usually included with the later versions of the Microsoft Windows operating system. Windows XP SP2, Windows Server 2003, and Windows Vista come with .NET built in. The .NET Framework is a fundamental Microsoft component and is intended to be used by most new applications created for the Windows platform.