In MongoDB tutorial of deploying geographically distributed replica set it is said that
Ensure that a majority of the voting members are within a primary facility, “Site A”. This includes priority 0 members and arbiters.
I am confused by arbiters there since in other place in documentation I found that
There should only be at most one arbiter configured in any replica set.
So how many arbiters at most can be in a replica set? If more that one arbiter allowed, then what is the point to have more than one arbiter in replica set?