Custom Forms are made up of Elements. This is a list of all of the Elements and their purpose.
Simple Text : Where you can add text to the form that does not require any action to be taken by the client. It is just for reading.
Text Box: Will create a box where your clients can enter a short amount of text. Text box is for one word answer while a text area is for a sentence or paragraph answer.
Text Area: where you can enter a larger box and clients can complete it by entering in a larger amount of text: an explanation to the question.
Check box: Where you can set an option and allow clients to select them by checking the box.
Section header: is if you need to enter a headline for a field. This text will appear darker in the form.
Single Option list: is a drop down list that allows you to enter options that your clients can select from when completing the form.