By hovering the mouse over the name of a database object, you can get additional information such as column and parameter names and data types.

QuickInfo is available for Tables, Views, Stored Procedures and User Defined Functions.

You can switch off the option of having Quick Info available when hovering the mouse (see changing options and preferences for more details). In this case you can also click the Quick Info toolbar button when the current caret position is within the desired object name.