silo 1. The FIFO input-character buffer in an RS-232 line card. So called from DEC terminology used on DH and DZ line cards for the VAX and PDP-11 , presumably because it was a storage space for fungible stuff that went in at the top and came out at the bottom. 2. Centralized internet social network system in which all of the user data belongs to one organization and resides within one server or set of servers owned by the organization. Silos typically employ the network effect and user interface antipatterns in order to keep their users trapped within the silo. The opposite of silo computing is decentralised or distributed computing.