What does `pip install unstructured[local-inference]` do?

I was following a tutorial on langchain, and after using loader.load() to load a PDF file, it gave me an error and suggested that some dependencies are missing and I should install them using pip install unstructured[local-inference]. So, I did. But it is now installing a whole lot of packages. A whole lot of it includes some packages to do with nvidia-*. Can someone please explain what this command does? It took a good couple of hours for this command to complete.

When you run "pip install unstructured," you simply install the "unstructured" package; no other dependencies are installed.

On the other hand, if you use the command "pip install unstructured[local-inference]", you additionally install the "local-inference" package as a dependency in addition to the "unstructured" package.

In situations when you must make predictions on data that is kept locally on your system, the "local-inference" package offers a collection of tools and utilities for doing local inference with machine learning models.

Additionally, as stated in the documentation, you may use pip install unstructured if you do not need to handle PDFs or pictures

It's the command that installs 'unstructured(https://pypi.org/project/unstructured/)' package. It's for pre-processing text documents such as PDFs, HTML and Word Documents.
So, it might be big and have many dependancies since it processes several types of documents.

the right method is:pip install "unstructured[local-inference]"

I installed unstructured already but I still had the same problem.

it seems like the correct way to do it is to do

pip install "unstructured[local-inference]"

instead of

pip install unstructured

here's the documentation that I got this info from:
unstructured