SQL server replication (publisher, subscriber, distributor) on top of AlwaysOn
This answer has been copied from the accepted answer on this question of Stack Ovweflow:
How to determine the SQL Server replication type by TSQL?

Run the following query on the distribution database:
SELECT 
     P.Publication
    ,P.Publication_type
    ,S.Subscriber_ID
    ,S.Update_Mode
FROM 
    MSPublications P
INNER JOIN 
    MSSubscriptions S
    ON P.Publication_ID = S.Publication_ID;

Publication_type:

0 = Transactional
1 = Snapshot
2 = Merge

Update_mode

0 = Read only
1 = Immediate update
2 = Queued update with message queue
3 = Immediate update with queued update as fail-over using message queue
4 = Queued update with SQL Server queue
5 = Immediate update with queued update as fail-over using SQL Server queue