Full Idea
There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives).
Gist of Idea
Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite
Source
JC Beall / G Restall (Logical Consequence [2005], 3)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.6