Textarea vs. Text
HTML offers two different field types for texts the textarea and the input that comes with different types like text, email, password...
The difference between these both HTML field types is, that the input creates a smaller single line input box, while the textarea creates a bigger box meant for longer texts, like messages. While you cannot force an input to become bigger than a single line, width and hight of a textarea can be set with the HTML attributes "cols" and "rows" and textareas feature by default a height of more than one row. In addition the textarea will show scroll bars, when the text, entered into it, takes more lines than the original height of the textarea provides.
Please note that for reasons of simpler form validation each input type is a separate field type in Visforms.