Form elements
Within your form you will find you have fieldsets and elements. Fieldsets can be thought of as logical containers for the elements. Every form is made up of at least one fieldset (which is there by default) and one element (which you have to add yourself - though only one element wouldn't make for a very complete form!)
Fieldsets
By default there will always be one fieldset in to which you put your elements and it is untitled. If you add the optional title to a fieldset it will be displayed on the resulting form.
The controls shown on a fieldset depending on how many elements there are or how many other fieldsets. For example, if you have more than one fieldset then you will see a drag handle with which you can re-order the fieldsets. If you have an empty fieldset (ie, one without any elements) then you will see a 'remove fieldset' option (except if there is only one fieldset - you're not able to remove the only fieldset).
Elements
When you add an element it will be added to the last fieldset in the list.
All the elements require the label to be completed (unless otherwise stated), which is the text that the user sees on the form. Most elements will also allow you to optionally add a description to the element which appears between the label and the actual form element in the rendered form.
To add a form element, select the name from the list and it will be added to the lastest fieldset. From here you can complete the information, drag and drop to reposition the fields and remove any that you no longer wish to be on your form. To make dragging/dropping a little easier you can use the show/hide details arrow next to each element, or show/hide all elements in the fieldset by using the fieldset-level show/hide arrow (watch the video for this to make more sense!) You can not onnly order elements within the fieldset but can also drag between fieldsets.
If you select to make a form element required then the form will not submit unless the user has entered information for that particular field.