$( ":text" ) allows us to select all <input type="text"> elements. As with other pseudo-class selectors (those that begin with a ":") it is recommended to precede it with a tag name or some other selector; otherwise, the universal selector ( "*" ) is implied. In other words, the bare $( ":text" ) is equivalent to $( "*:text" ), so $( "input:text" ) should be used instead.
Note: As of jQuery 1.5.2, :text selects input elements that have no specified type attribute (in which case type="text" is implied).