anisble playbook - update only redhat

How can we solve conditions in ansible? 

Ansible is very simple: We want to os update but only on Redhat machines? How? 

Like this:

 ---

- hosts: all

  tasks:

    - name: "update OS"

      command: yum update -y

      when: ansible_os_family == 'RedHat'

      when: ansible_os_family == 'RedHat' - it is condition -- only RedHat OS family (like RHEL, Centos, etc..)

playbook: https://gitlab.com/martin.suraba/ansible-playbooks-linux-os/-/blob/main/playbooks/yum_update_only_RedHat.yaml