The text field type should be any text-like type in your database. text is the default field type, so setting the type property isn't required.
'name' => array(
'type' => 'text', //optional, default is 'text'
'title' => 'Name',
'limit' => 30, //optional, defaults to no limit
)
In the edit form, an admin user will be presented with a simple text input.
The limit option lets you set a character limit for the field.
The text field filter lets you search for items that match a given string in that field.