Playbook formatting question

Can someone please let me know what is wrong with my playbook (below) formatting. I get the following error message when I run the playbook.

ERROR! ‘copy’ is not a valid attribute for a Play

The error appears to have been in ‘/etc/ansible/playbooks/copy_files.yml’: line 3, column 4, but may

be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

This is not a playbook it's task.

A minimum required reading is
https://docs.ansible.com/ansible/2.6/user_guide/playbooks_intro.html

Preferably you should read the whole user guide
https://docs.ansible.com/ansible/2.6/user_guide/index.html