Identifiers (continued)

Why do we need identifiers?

The same word can be used for different things. Humans manage this fairly well, but computers do not. If the thing has the same name, to a computer it has the same identity. So a computer will not know the difference between a terrier and a weiner if they are both referred to with the name "dog."

Using identifiers, each different thing gets a different name, in the form of an identifier. The identifier won't be used in human interaction, but is essential for the computer to distinguish between different things which may have the same name in the human world.

Another advantage of identifiers is that they are not dependent on any particular human language.

Since identifiers are for computers, it is common to have a display form for the human user. There can be as many different display forms as there are languages, with each language coded with a standard language code. This makes sharing of data across languages relatively simple. Everyone can see and search and work with the metadata in their own language, but because they are all using the same identifier there is no translation needed when exchanging data.

 

This lecture continues...