K to M
Layers are map overlay displays of spatial information that represent themes of data that can be switched on and off as the user desires. Layers may include spatial information such as soil, rock, populations, rainfall etc. ().
A legend is an explanation of the symbols, codes, names given to variables and other information appearing on a map drawing or chart. It includes a sample of each symbol, line pattern, shading, or hatching appearing on the map along with annotations describing the meaning of each (http://www.kam.to/kam/services/gisdictionary.cfm).
Linux is a computer operating system and its kernel. It is one of the most prominent examples of free software and of open-source development and all of its underlying source code is available to the public to use, modify, improve, and redistribute it. In the narrowest sense, the term Linux refers to the Linux kernel, but it is commonly used to describe entire Unix-like operating systems (also known as GNU/Linux) that are based on the Linux kernel combined with libraries and tools from the GNU Project and other sources (http://en.wikipedia.org/wiki/Linux)
The map window is the active window used for viewing various map features and images in a GIS. In IMF the map window is also used to view the North arrow and the scale bar.
A Markup is a sequence of characters, often called tags, inserted at various places within a particular text, or word processing file e.g. a HTML web page. These characters are used to show what the file would look like if it were to be printed out or displayed (http://www.google.co.za/search?hl=en&q=define%3A+Markup&meta=).
Metadata literally means "data about data" and is information that describes another set of data. A common example is a library catalogue card, which contains data about the contents and location of a book: It is data about the data in the book referred to by the card. In a GIS metadata is data about the data that makes up the spatial features in a coverage
Microsoft Corporation is the world's largest software company and develops, manufactures, licenses, and supports a wide range of software products for computing devices. Its most popular products are the Microsoft Windows operating system and the Microsoft Office suite of productivity software, each of which has achieved near ubiquity in the desktop computer market (http://en.wikipedia.org/wiki/Microsoft).