DO180 - Chapter 7s06 - Diff between oc tag vs oc create istag ?

[cipid2001_linux]

Hi, 

   What is the functional difference between these 2 commands regarding the tagging of an image stream ?  

$oc create istag versioned-hello:v1.0 --from-image registry.ocp4.example.com:8443/redhattraining/versioned-hello:v1.0

$oc tag registry.ocp4.example.com:8443/redhattraining/versioned-hello:v1.0 versioned-hello:v1.0 

   From my point of view, both are doing the same thing.

Thank you!

[cipid2001_linux]

It is mentioned in the next chapter (ch7s07) that the following commands performed the same operation: 

[user@host ~]$ oc create istag keycloak:20.0.2 --from-image quay.io/keycloak/keycloak:20.0.2
[user@host ~]$ oc import-image keycloak:20.0.2 --from quay.io/keycloak/keycloak:20.0.2 --confirm
[user@host ~]$ oc tag quay.io/keycloak/keycloak:20.0.2 keycloak:20.0.2