How does game “optimization” work? Are people sitting there changing lines of code to more “optimal” ones? What is “optimized”?

Question

The recent The Last of Us for PC made me realize I had no idea what’s meant by “optimizing” a game.

Same with optifine in Minecraft improving performance. How do these things work to just make games use fewer resources?

In: 158

Answer 1

“optimized” (as an example) is loading the same skin texture for separate assets just once (instead of loading it each time for each asset.)

and then making sure that you really need to load 18,000 different textures instead of, maybe, 500 or so.