[quote=@BladeSS4]
The 'secret' technique.  This is things like Afterimages and general other special moves right? 
[/quote]

Absolutely correct!

An after image technique would be an example of a Speed based technique.
Ki blasts and pump up techniques would be for attack.
Hardening defensive stances and ki shields would go for defense. 

Secret techniques are NOT charged attacks like the Spirit bomb or a powered up Kamehameha. Although, a quick Kamehameha could be a secret technique.