What is the role of references in C++?

In C++, a reference is a mechanism that allows a variable to be given an alias at the time of declaration. It serves several purposes:

1. Alias: Alias allows for one existing variable to be given an alternate name, allowing both names to refer to the same object. This allows for access and manipulation of the original variable through the alias, without the need for extra pointer indirection or copying of the original data.
2. Passing Function Parameters: Passing by reference can be used as a function parameter, allowing for direct modification of the original variable without the need for passing through pointers or returning values.
3. Avoid copying: using references in function calls can avoid unnecessary object copying and improve program performance efficiency.
4. Simplify code: using references can simplify code writing, making it more concise and easier to read.

It is important to note that references must be initialized when declared and cannot change the object they are bound to. Additionally, unlike pointers, references do not require the use of the dereference operator (*) to access the object they refer to.