Why is Ollama so easy to start with?
Ollama collapses the steps of running a local model into one command. You ask for a model by name, it downloads the file, picks reasonable defaults, and starts it. From there you can chat with it at the command line or call its local API (application programming interface) from your own code. The model files and the fiddly choices about how to load them are handled for you, which is most of what makes the first run hard with lower-level tools.
That convenience is built on top of llama.cpp, the C++ inference engine. Ollama adds the friendly interface and the model management, and llama.cpp does the actual work of running the model underneath. So it inherits the same strengths: it runs on modest hardware, and it serves models in the GGUF file format.
When should you move past it?
Ollama is built for one person exploring models on one machine, and it is very good at that. The trade for its convenience is control. When you need to serve a model to many callers at once, squeeze maximum throughput from a large graphics processor (GPU), or tune low-level flags for specific hardware, a server built for that job fits better. Many people start with Ollama to learn what a model can do, then graduate to a heavier serving engine when the workload outgrows a single desktop.