Crop marks and bleed both act as a guide for printers to effectively and accurately print desired collateral. The Badge Creator tool found within the Entegy Core allows for these configuration options to be set when generating badges. The exact settings for these two options will depend on the printer you are utilising and the size of the stock you will be printing onto. Generally, a bleed of 3mm is more than sufficient.
More specifically, a bleed refers to the practice of extending a design slightly to ensure an accurate print job. It's impossible for a printer to perform a clean cut when printing and without the addition of a bleed, your design may become slightly misaligned in the cropping process - not at all desirable. Crop marks simply act as a guide for your printer so that they know where exactly to crop.