What is the difference between Assignment Data Lookup & Assignment Rule?

[Jaykumar Pancha]

What is the difference between Assignment Data Lookup and Assignment Rules?

I have created Rule and Data Lookup both for same category "Hardware". But it's conflicting with each other and I wan to know why it is conflicting?

1) Created Data Lookup:

• Assigned to Hardware group when choose Hardware category.

2) Created Rule:

• Assigned to Hardware group and winnie.reich person too when choose Hardware category.

#Assumption

Assumption is when create a new incident and choose Hardware option from category list then, it should be assign to Hardware (assignment group) and winnie.reich (assigned to).

#Expected

Assign to Hardware assignment group and winnie.reich assigned to

#Actual

It assigns only to the "Assignment Group".

[Jaykumar Pancha]

Answer is there in community post as @Ethan Davies mentions in his reply.

As per my understanding is, Priority is the key role. 

1. Priority is another example of lookup rules, where priority is combination of Impact & urgency.
2. I prefer lookup rules as it sets the assignment group before the ticket is inserted/updated.