If there are human beings in your photo, you need to get the model release signed for the photo to get accepted as Royalty Free. If there are news worthy images where you cannot get a model release signed, you can submit it as editorial. This not only applies to humans, but also to buildings, cars, art, etc.. Photos with cultural significance will have to be submitted as editorial, if you don't hold a model release.
The following links will give you more information
@Jetcityimage: Please keep in mind that the editorial images should reflect events from social, cultural, political scenes etc. You need to ensure your image is appropriate for this section before submitting it. You cannot submit any person or building image for which you do not have a release as some may not fit this section.
@Dreammack77: The differences between the two licenses can be read on our terms - RF is meant for commercial usage and can be used in editorial contexts while editorial is meant exclusively only for editorial usages and contexts: Royalty free Editorial
The royalties awarded are the same, with the exception that the editorial images cannot be sold under commercial licenses such as Web license W-EL, Print license P-EL and sell the rights license SR-EL. Sell images