Google's mantra is "organizing the world's information." If you're organizing information in your corporation or organization, that might not be a viable option. URIs present the opportunity for everyone in a web environment to make a step in that direction.
One of the major challenges for large organizations is that different people, departments, etc. use the same words to mean different things. Every business and subset of business has "terms of art", often common words or phrases that mean something special to that group.
To a programmer, the word "beta" means the test of software before it's released for general use. To a stock broker "beta" is a number that shows whether a stock is more or less volatile than the market. They're in diffferent industries so, talking face-to-face, it's pretty easy to tell that they're talking about different things.
There are plenty of examples, though, where the same word in the same industry means different things. In the financial industry, "wealth" is used to define the threshold for accepting clients for certain services. Every institution picks its own number and they can be the same or different (e.g., over $1 million in net worth; over $1 miillion in liquid funds invested; over $1 million in assets other than personally-used real estate). When those institutions merge, the inconsistent definitions become an impediment to merging their data.
In computer systems, there historically weren't good ways to know which meaning someone had in mind when they put a particular word in a file or database. The problem was the same for the names of fields or columns. Now, we have metadata...data that let's us provide information about data. So, we can stick tags on data in a file that tells us things like where it came from, what day it was collected, or what size it's supposed to be.
A URI (uniform reference identifier) can store the definition you have in mind. So Citi/define/wealth can have a different meaning from UBS/define/wealth. And, your system can point to the appropriate one whenever "wealth" appears in your data. This makes it possible to merge data and retain different meanings or to compute across disparate meanings.