In MIPS, temporary registers like $t0 to $t9 are split into two groups based on who is responsible for saving their values during function calls.

Caller-Saved Registers ($t0 to $t9): These are used for temporary data that doesn't need to be saved across function calls. When a function calls another function, it's up to the calling function (the one making the call) to save these registers if it needs their values later. The function being called (the callee) can change these registers freely, so the caller must save them if needed.

Callee-Saved Registers ($s0 to $s7): These registers are meant for values that need to be preserved across function calls. If a function uses these registers, the called function (the callee) is responsible for saving and restoring them. This way, the calling function doesn't lose important values.

Why this split? This split helps make function calls more efficient:

The caller only has to worry about saving temporary data if needed, which reduces the work it has to do. The callee ensures important data stays intact, but it only has to save and restore the values that really matter. This design helps avoid unnecessary work and keeps things running smoothly during function calls.