Set - 5

Question 26 :

What is URL ?

Answer :

Uniform Resource Locator. A standard for writing a text reference to an arbitrary piece of data in the WWW. A URL looks like "protocol://host/localinfo" where protocol specifies a protocol to use to fetch the object (like HTTP or FTP), host specifies the Internet name of the host on which to find it, and localinfo is a string (often a file name) passed to the protocol handler on the remote host.


Question 27 :

What is URN ?

Answer :

Uniform Resource Name. A unique identifier that identifies an entity, but doesn't tell where it is located. A system can use a URN to look up an entity locally before trying to find it on the Web. It also allows the Web location to change, while still allowing the entity to be found.


Question 28 :

What is variable ?

Answer :

An item of data named by an identifier. Each variable has a type, such as int or Object, and a scope. See also class variable, instance variable, local variable.


Question 29 :

What is virtual machine ?

Answer :

An abstract specification for a computing device that can be implemented in different ways, in software or hardware. You compile to the instruction set of a virtual machine much like you'd compile to the instruction set of a microprocessor. The Java virtual machine consists of a byte code instruction set, a set of registers, a stack, a garbage-collected heap, and an area for storing methods.


Question 30 :

What is void ?

Answer :

A Java keyword used in method declarations to specify that the method does not return any value. void can also be used as a nonfunctional statement.