A typical diffusion constant for a medium-sized molecule in water is about . If we want the smell to travel a quarter mile, or a little less than , we get a speed of. This speed is fantastically slow, and says that it would take ten million years for blood to diffuse out to a shark a quarter mile away.
XML Parser. A parser is a piece of program that takes a physical representation of some data and converts it into an in-memory form for the program as a whole to use. Parsers are used everywhere in software. An XML Parser is a parser that is designed to read XML and create a way for programs to use XML. There are different types, and each has its advantages. Unless a program simply and blindly copies the whole XML file as a unit, every program must implement or call on an XML parser.
XML (Extensible Markup Language) files don't do anything on their own. They are simply a way of storing data that can be easily read by other programs. Many programs use XML to store data. As such, you can open, edit, and create an XML file in any text editor. XML is similar but distinct from HTML. XML is for carrying data, while HTML is for displaying it. HTML uses predefined tags, such as <p> or <h1>, while XML uses any tags that the creator needs.