The skeleton

## With the symfony cli

# run this if you are building a traditional web application
$ symfony new my_project_name --full

# run this if you are building a microservice, console application or API
$ symfony new my_project_name

## Without the symfony cli

# run this if you are building a traditional web application
$ composer create-project symfony/website-skeleton my_project_name

# run this if you are building a microservice, console application or API
$ composer create-project symfony/skeleton my_project_name

To have an ORM:

composer require symfony/orm-pack

To have a serializer:

composer require serializer

To have ORM annotations in your code you need doctrine/annotations, install with:

composer require doctrine/annotations