Now that is a good question.
There is a difference between conditioning and getting beer into good condition also known as ageing.
Conditioning means getting it a bit fizzy, straight forward. In lager production they have conditioning tanks where it gets fizzy over a long period of time.
Getting it to condition/age I've yet to find anything really definitive. There is acceptance that if you leave beer in a bottle/barrel for a while it gets better and the higher the ABV the longer you leave it but I can't find anything that explains this.
Anyone ?
There is a lot of yes and no surrounding this subject and a lot of it is opinionated, very little is ever supported by concrete evidence cause people always argue indifferently.
Conditioning doesn't meant 'getting it a bit fizzy' at all as typically the beer these days would be pumped to the conditioning tank through a filter to remove any yeast and any oxygen will have been removed by fermentation , this leads to the beer being pumped flat but relatively bright for a short spell maturing before being pumped with CO2 and heading off to the racking plant.
The other kind of conditioning is unfiltered in which the beer would be pumped a few degrees above gravity to conditioning tanks where it will continue fermentation before being passed on to the racking plant and being racked a couple of points above final to give us cask conditioned ale. Again, entirely different if ester, flavour and aroma profile.
Achieving condition again is an entirely different kettle of fish, there is no such thing as 'good' condition, only perfect condition which is when the beer is judged to be at its prime after a spell of mauration and spiling, ageing again is different as ageing refers to beers kept for long periods of time and becoming stale (aged).
Maturation is the period where the beer is handled and made ready for consumption at the peak of its profile, this profile consists of more than one element not limited to the alterations of flavour compounds given by the secondary fermentation of the yeast, the vessel the beer is being held in and the correct level of carbonation.
There is a lot when it comes to someone asking about conditioning beer as there are several varieties of the meaning.
I'm sure someone will disagree with me but I hope it helped give a little insight, not to bad mouth Twostages comments as he knows his stuff as well as the next man.
Cheers