Why Are Other Servers In Backup Tables?

I ran the following code on one of our servers and I got some surprising results. Those results included backups for that machine but also showed entries for other servers. I don't understand it! I can understand the results being wrong because I coded something incorrectly, but why would another server be listed in bs.server_Name? It appears that the entries are "correct" in that backups were taken on the other server at the time given, but why is it there??? (I put the code together to list the most recent backup for each database on the instance. I hope it is correct.)

select @@ServerName, bs.server_Name, bs.Database_Name,
bmf.physical_Device_Name,
bs.backup_start_date, bs.backup_finish_date,
Case When bs.backup_start_date < Getdate() - 1 Then 'Stale' Else 'Recent' End as Status,
Case When bs.backup_finish_date is NULL Then 'Failed' Else 'Successful' End as Success
from msdb.dbo.backupset bs
Join msdb.dbo.backupmediafamily bmf on bmf.media_set_id = bs.media_set_id
where type = 'd'
and bs.backup_set_id = (select max (bso.backup_set_id)
from msdb.dbo.backupset bso
where bso.server_name = bs.server_Name
and bso.Database_Name = bs.Database_Name
and bso.Type = 'D')
order by database_name