installing laravel --prefer-dist

It's all available here: https://getcomposer.org/doc/03-cli.md#install

--prefer-dist: Reverse of --prefer-source, composer will install from dist if possible. This can speed up installs substantially on build servers and other use cases where you typically do not run updates of the vendors. It is also a way to circumvent problems with git if you do not have a proper setup.

--prefer-dist and --prefer-source are the two options of composer which included in various documentations with a lack of proper explanation.

--prefer-dist would try to download and unzip archives of the dependencies using GitHub or another API when available. This is used for faster downloading of dependencies in most cases. It doesn't download the whole VCS history of the dependencies and it should be better cached. Also archives on GitHub could exclude some files you don't need for just using the dependency with .gitattributes exclude directive.

--prefer-source would try to clone and keep the whole VCS repository of the dependencies when available. This is useful when you want to have the original VCS repositories cloned in your vendor/ folder. E.g. you might want to work on the dependencies - modify them, fork them, submit pull requests etc. while also using them as part of the bigger project which requires them in the first place.

Simply speaking, the --prefer-source option will prefer to create a package directory that is a "version control repository", which is equivalent to you typing:

$ git clone ...

or

$ svn checkout ...

On the other hand, the --prefer-dist option will prefer to create a non-"version control repository", which is equivalent to you typing:

$ git clone ... ; rm -fr dir/.git

or

$ svn export ...

Remember that, these are only preferences, if a dependency is required using a VCS repository which does not provide archives such as GitHub API, then the only available option is to clone the repository.