The Camera and Attachments fields within a form template are very similar, as they both allow the individual who is completing the form to be able to upload files into the report. The difference between each of these field types is the type of files that you can upload to them.
The Camera field type will accept most types of image files (jpg, png, pdf, etc), but not other file types. Attempting to upload other files may prevent the Report PDF from being able to generate. Also pictures can be uploaded in bulk, rather than individually, so if there are a number of saved images on your mobile device or computer, they can be uploaded together in groups.
Note: If your report PDF will not load, check the images that are attached. If there are any that are showing a broken image link, then that may be what is preventing your PDF from generating. Deleting and reuploading the image will fix it.
The Attachment field will allow most file types to be uploaded / attached to the form as extra files that can be opened from the Report PDF. This is good if you have information sheets or brochures that you would like to attach. Images can also be uploaded as attachments as well.
Note: When uploading an Attachment file from a mobile device, you can only upload one at a time and will be asked to provide extra details for it, such as a name or any notes that you'd like to accompany the file. Those details are optional, and you can simply click 'Upload' without filling them in if you want.