The discriminant tells us there are two roots when positive, one root when zero, and no roots when negative. b^2-4ac = (-8)^2-4*3*1 = 52 is positive, so there are two roots. The discriminant is just part of the quadratic equation. The quadratic equation gives us the exact real number roots of any equation in the form ax^2+bx+c=0. The quadratic equation is x = (-b \pm sqrt(b^2-4ac))/(2a), where \pm means that we have two values, one using + (addition) and one using - (subtraction). Let D = b^2-4ac.
RE: what is the difference between database and data w... Database is the place where the data is taken as a base and managed to get avialable fast and efficient access. Dataware house is the place where the application data is managed for analysis and reporting purposes.
Different vendors use these terminologies to mean different things. In Oracle-speak, a database is the collection of datafiles on disk. These datafiles belong to your tablespaces. They are also the online redo log files, the parameter file, the password file, and the control files. A database exists on disk and will be there even if you shut down the server and reboot it. But a database is not accessible by itself. You have to sign on to SQL*Plus and issue a STARTUP command.