differences between a titled land and a tax dec

Hi to every body, I was reading a lot of interesting 3ads in here.
I am Max from Italy, actually located in Bantayan Island (Cebu) with my Filipina wife and 2 kids.
We are planing to buy a land over here, on my wife' s name, or a company 60/40.
They was offering us as a title, 2 kind of lands: titled and taxdec.
Some gentlewoman or gentleman, may explain to me, please, what's the real differences between this 2.
If we buy , for example 3000 sqm of land , how maximum big can be the house that we will build on, for a private residency, or in case we will want to build a resort?
I add a last question: the right procedure to buy (lawyer; notary; public registrations)
I was lawyer in Italy, for 10 years and now, I' m in real estate in there and i hope, one day, to give you all the same help and Tip, in case you' ll want to buy a house in there.
Tnx to all.
Max Gibelli

Nobody know the the answers or did I made same mistakes of presentation in this forum?
I was hoping that between lawyers we was helping eachothers....
Best.
Max Gibelli

title is a conclusive proof of ownership; tax dec is just an evidence of claim of ownership.

email me if you have concerns at reclusionperpetua78@y.c.