The image settings are used when using the attachment field type.
Maximum image width:Width that jpg, gif or png is resized to.
Maximum image height:Height that jpg, gif or png is resized to.
Thumbnail image width:Width of thumbnail generated when uploading jpg, gif or png.
Thumbnail image height:Height of thumbnail generated when uploading jpg, gif or png.
Max image size:Total maximum size of all attachments on your form. Should not exceed your php max_upload_size.
Save History:Do you want content versioning turned on?
Maximum versions:When save history is turned on, how many versions do you want to retain?
Encrypt form:This forces the form submission to use SSL
Do not store results:When set to yes, data is immediately deleted once the notification email is sent. For more information, refer to Advanced features -> Protecting Personal Information - do not store data.
Debug:When set to yes, extra information is shown which may help with troubleshooting issues.