Aliasing in the context of programming languages refers to :

Definition: Aliasing occurs when two or more variables refer to the same memory location.

Key idea: If you modify the value through one variable, that change is visible through the other variables that alias the same location.

• Example in C: int x = 5; int *p = &x; int *q = p; — p and q refer to the same memory location (they alias x).

• Example in Python: a = [1]; b = a; b.append(2) — a and b refer to the same list, so changes via b are visible via a.

Consequences: Aliasing affects program behavior and reasoning because updates through one name affect all aliases.

• Can cause unintended side effects with mutable objects; use copies when you need independent data.

• Is important for compiler optimizations and correctness reasoning (compilers must account for possible aliasing when transforming code).