What is Ollama?
The runner that turned running a local model into a single command, and the reasons research work eventually wants more around it.
Ollama is a free tool that runs large language models on your own machine with a single command. It bundles the inference engine, downloads the model you name from its library, and starts serving answers locally, hiding the file management the underlying stack would otherwise ask of you. Its limits are the flip of that simplicity: it is a runner, not a research workspace.
One command, whole stack.
Underneath, Ollama uses an engine from the llama.cpp family to run the model, and the files it downloads are GGUF files like any other local tool reads. What it adds is the wrapper: type a model's name and it fetches the right file, loads it, and exposes a local service that other programs can send questions to. The setup that used to mean choosing an engine, finding weights, converting formats and writing a launcher becomes a command and a wait for the download.
What it is good at.
Its natural habitat is experimentation and serving. Trying a new model costs one command, comparing two means two commands, and the local server interface makes it a backend for scripts and small tools. Privacy comes free with the architecture, since the model and its conversation run entirely on your machine, with no account and no telemetry in the loop. For learning what local models can and cannot do, and for wiring one into a small project, it is the shortest path available.
Where you outgrow it.
A runner serves a model; it does not manage a library, and most research work is library work. Grounded reading, where answers are built from retrieved passages of your own documents and checked against them, needs a document store, an index and a citation discipline that sit above the engine, not inside it. That layer is what desktop research tools add. The runner remains underneath either way, which is why knowing what it does still pays: when an answer arrives slowly, the bottleneck is usually in the runner's settings, not in the application above it.