IMPORTANT
All Nodes must belong to an organization, you bootstrap nodes to that organization.
Use knife node <sub-command> to manage nodes
So what is bootstrapping? When we attach a node to our Chef server, often, we'll need to actually install the Chef client so that we can run or execute our cookbooks. The node may not have any idea of how to contact your Chef server either. So the process of bootstrapping is installing the Chef client and telling that node where your Chef server is located. The bootstrapping command is available with knife bootstrap.
Common syntax for the bootstrap command is
shell command
knife bootstrap <FQDN/IP> -x <user name> -P <password> --sudo -N <node name> -r "recipe[cookbook]"
OR
knife bootstrap <FQDN/IP> -i <identity file like a .pem file> --sudo -N <node name> -r "recipe[cookbook]"