templates format the data so people who aren't into dealing with the raw hex data. they aren't absolutely necessary, but you have to be more comfortable working in hex than i am, and i've been known to write programs in s19 assembly. you can get the templates online (i'm too lazy to look them up) or you can make them on your own, and once you have them you just have them in an open file while you work on your plug (i usually just copy them into the plug i'm working on so i don't have to worry about opening the templates afterwards). resedit will automatically use the templates if you have them in there, which will turn a typical dude from something like:
0003 00A0 00A0 00A0 00A0 0019 0019 0019 0019 00B4 0000 0FAA
into something like:
AI Type: 3
Ship Types: 160 160 160 160
% Prob: 25 25 25 25
Govt: 180
Booty: $0000
Info Types: 4010
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if you find yourself in bed with a raving lunatic, don't worry: looks can be deceiving, it's probably not me