Error trying to create a new vm in ansible - ansible

Question

I just started learning Ansible. It has been a pain so far. I have this code to create a new vm. I followed this tutorial.
---
- hosts: localhost
connection: local
tasks:
- vsphere_guest:
vcenter_hostname:1.1.1.12
username: root
password: pasword
guest: newvm001
state: powered_on
validate_certs: no
vm_extra_config:
vcpu.hotadd: yes
mem.hotadd: yes
notes: This is a test VM
folder: MyFolder
vm_disk:
disk1:
size_gb: 10
type: thin
datastore: storage001
vm_nic:
nic1:
type: vmxnet3
network: VM Network
network_type: standard
vm_hardware:
memory_mb: 256
num_cpus: 1
osid: ubuntu64Guest
scsi: paravirtual
esxi:
datacenter: 1.1.1.12
hostname: 1.1.1.12
I however keep getting this error.
[WARNING]: Host file not found: /etc/ansible/hosts
[WARNING]: provided hosts list is empty, only localhost is available
PLAY [localhost]
TASK [setup]
******************************************************************* ok: [localhost]
TASK [vsphere_guest]
*********************************************************** fatal: [localhost]: FAILED! => {"changed": false, "failed": true, "msg":
"Cannot find datacenter named: 9.1.142.86"}
NO MORE HOSTS LEFT
************************************************************* [WARNING]: Could not create retry file 'testing.retry'. [Errno
2] No such file or directory: ''
PLAY RECAP
********************************************************************* localhost : ok=1 changed=0 unreachable=0
failed=1
Why is that so? And what is the difference between a host file and an inventory file?

Answer 1

what is the difference between a host file and an inventory file?
They are the same. However, since you're doing everything on your local machine, it's fine that you only have localhost available.
This is your error:
TASK [vsphere_guest] *********************************************************** fatal: [localhost]: FAILED! => {"changed": false, "failed": true, "msg": "Cannot find datacenter named: 9.1.142.86"}
It's not clear to me why you're receiving this with the playbook you've provided, as it doesn't mention that IP at all and the line I suspect is causing the problem is
datacenter: 1.1.1.12
Are you sure this is the file you're running, and that you've saved any changes you've made to it?