Stack of activation records

A stack is a linear data structure with LIFO access strategy: LIFO stands for Last-In-First-Out, which means that the last element that entered the stack is the first element that leaves the stack among those present (confront with a stack of plates).

At run-time, the JVM manages the stack of activation records (AR):

• for each method activation a new AR is created on top of the stack;
• at the end of the method activation, the AR is removed from the stack.

Each AR contains:

• the memory locations for the formal parameters, including the reference to the invocation object (if the method is not a static one);
• the memory locations for the local variables (if present);
• the return value for the method invocation (if the method has a return type different from void);
• a memory location for the return address, i.e., the address of the next statement to execute in the calling method.