An object’s scope means its visibility to other classes, module, procedure etc. There are two types of scope in Visual Basic projects: variable scope and procedure scope. Variable Scope : There are three levels of variable scope in Visual Basic: at the procedure level, at the form or module level, and at the global level. Visual
Projects can become quite advanced in Visual Basic, even containing sub-projects of different types. From a programming point of view, however, standard Visual Basic projects usually contain just three types of items: global items, forms, and modules. Forms: They are the templates you base windows on. Besides standard forms, Visual Basic also supports Multiple Document Interface
The possible variable types and their ranges : Variable type Bytes of Storage Range Boolean 1 True or False Byte 1 0 to 255 Currency 8 -922,337,203,685,477.5808 to 922,337,203,685,477.5807 Date 8 1 January 100 to 31 December 9999 and times from 0:00:00 to 23:59:59 Decimal 12 -79,228,162,514,264,337,593,543,950,335 to 79,228,162,514,264,337,593,543,950,335 Double 8 -1.79769313486232E08 to 4.94065645841247E-324