# Learn to use OPAM in 2 minutes

This short tutorial covers the very basic use cases to get you started with OPAM. A more lengthy introduction can be found in the Advanced Usage guide.

## Initialising OPAM

    opam init

This will create the `~/.opam` directory, within which packages will be installed and where OPAM will store its data.

## Browsing available packages

The following commands will enable you to obtain information on available packages:

    opam list -a            # List all available packages
    opam search QUERY       # List packages with QUERY in their name or description
    opam show PACKAGE       # Display information about PACKAGE

You may prefer to browse them online. If you find a package there but not on your computer, either it has been recently added and you should simply run `opam update`, or it's not available on your system or OCaml version -- `opam install PACKAGE` should give you the reason.

## Installing a package

The two commands you will probably use the most with OPAM are:

    opam update             # Update the packages database
    opam install PACKAGE    # Download, build and install the latest version of PACKAGE

## Upgrading your installed packages

You may want to regularly issue these commands to keep your packages up-to-date:

    opam update             # Update the packages database
    opam upgrade            # Re-install packages that were updated since last upgrade

## Do more with OPAM

If you need more details and options, OPAM is self-documented through

    opam --help

To learn how to use more advanced features of OPAM (package pinning, multiple repositories, multiple compilers...), move on to the Advanced Usage guide, or the Packaging tutorial.