Symfony history
Symfony 2:
bundles system
dependency injection container
twig
console
Symfony 3:
symfony flex
psr-3: logger interface
workflow
Symfony 4:
focus on microservice, console applications and apis
autowiring system
symfony messenger
httpclient
Symfony 5:
symfony notifier (sms, slack, email, push…)
Symfony 6:
attribute based configuration