Step 1: Recall the full form of URL.
URL stands for
\[
\boxed{\text{Uniform Resource Locator}}
\]
It is the unique address of a resource available on the Internet.
Step 2: Understand its purpose.
A URL specifies the location of a web page or online resource and the protocol used to access it.
For example,
\[
\texttt{https://www.example.com}
\]
is a URL.
Step 3: Analyse the options.
• (A) Universal Resource Locator -- Incorrect. "Universal" is not the correct expansion.
• (B) Uniform Resource Locator -- Correct.
• (C) Unified Routing Link -- Incorrect. This is not a standard computer term.
• (D) Universal Routing Location -- Incorrect. This is not the correct expansion.
Step 4: Final conclusion.
\[
\boxed{\text{URL}=\text{Uniform Resource Locator}}
\]
Hence, the correct option is \(\boxed{(B)}\).