is straightforward. You load the weights, load the data, and wait for it to finish. For most models, that’s fine, and the only real cost is time. When the wait gets too long, the usual fix is to add GPUs. Each one trains on a different slice of the data in parallel, and the work finishes faster. Nothing about the model state changes; you’ve just thrown more hands at it. That covers the common case, where the problem is time. Large models add a second problem that more hands can’t solve: space.