(Official) Exchange trading is the structured manner in which assets are exchanged on the market between investors. 
Stringent rules that regulate trading are the basic characteristic of this modality. Each parameter is defined in advance by each stock exchange in question and by the Institutions, that, in a broad sense, supervise the exchange. An example of standardised exchange in the (Official) Exchange is the futures contract. The stock exchange is the physical site where regulated exchanges take place, which differs from Over-the-Counter (OTC) trading, which can be held on any other platform. In Italy, the official stock exchange is Borsa Italiana S.p.A.. Nowadays, stock exchanges themselves are listed on their own stock market. Borsa Italiana S.p.A. offers post-settlement services offered by Cassa di Compensazione e Garanzia S.p.A. and by Monte Titoli S.p.A. with fair, transparent and non-discriminatory rules. These services are given on the basis of interoperability, security, and equal treatment between market infrastructures and individual or institutions that request them and who are entitled according to the current national and/or European regulations. 
Ciciretti, R., Trenta, U., 2006, La Borsa Europea. Una Visione d’Insieme, in Rapporto sul Sistema Finanziario Italiano 2006, ARACNE, Roma;
Editor: Rocco CICIRETTI