please respond. to. James with 150. words 
which component of the fire sprinkler is your selected puzzle piece;
For my component, since a classmate already chose FDC, I will discuss the standpipe system. Specifically the Class I system. The Class I system is the single 2-1/2″ hose connection as outlined in NFPA 14. The Class II system has an 1-1/2″ hose connection for use by trained personnel and the Class III system is operated by both fire department personnel and trained, on-site personnel using both 1-1/2″ and 2-1/2″ discharges. 
when does that component activate;
As part of the supplemental system, the FDC can provide a standpipe, or support the sprinkler system in an effort to either control means of egress for escaping occupants or protect commodities. The standpipes in my jurisdiction are not generally “wet” standpipes. They are typically dry until the FD pumps water into and up to the corresponding floor. Our SOP is connection at the floor below the fire. However, more and more we’ve been seeing standpipes that charge with water upon receipt of a water flow alarm in the sprinkler system. The column of air is replaced by a column of water, thus reducing the time it takes the nozzle attack team to effectively wet their line and get water on the fire. 
where, why, or how is the component used
Typically, the standpipes are located in stair towers. The UFC and UCC in NJ determine the size, locations, and distance traveled to place standpipes. Our local ordinance also requires FDC’s and standpipe connections to be within 50′ of a hydrant, so the FD can quickly supplement the fire attack. In a typically standpipe building for us, which is a multi-family apartment, there will be two stair towers. One is designated as ‘attack’ and the other as ‘rescue’. Each will have a standpipe in them, but we delineate this so we can separate the two concurrent efforts, but still be able to adapt with the situation.