The Railroad Retirement Board will collect your Medicare premiums (if you have them) and premiums. If you receive railroad retirement benefits or railroad disability annuity checks, your Medicare premiums will be automatically deducted from your check each month.
The link is the physical and logical network component used to interconnect hosts or nodes in the network and a link protocol is a suite of methods and standards that operate only between adjacent network nodes of a local area network segment or a wide area network connection.
While the other answerers are correct that there's no difference in the *protocol* or commands, there is a difference in both speed and physical connection. An ATA connection is a parallel connection, sending many bits at once through a wide, flat connector.