Processing classifications indicate how long processing time will take for a specific product. There is no need to ask what processing type it is, as it is always noted in the listing details.
"Ready to Ship" items have already been created or are pre-made items (like stickers) that I carry in my shop. These items have an average* processing time of 2-10 business days. (Monday - Friday)
"Made to Order" means it needs to be created. It will be handmade on demand just for you! ^-^ The exact estimated* time varies per item and is specified in the listing description. These estimates are based on how long it has taken me to make these items in the past and how many orders I get at a time. This term covers things like "custom orders," "artist's choice," select "Wholesale," and "Request a Remake" items.
"Pre-Order" means I do not have it in stock. I am going to order it when it's been funded. I put a LOOSELY estimated time in the listing. Since pre-orders are funded by my customers, they have the most unpredictable processing times. Example: let's say I need 10 orders of an item to bring it to the shop. I could get 10 orders in a week which brings them faster. It could also take a month to get those 10 orders. My time estimates are only based on the number of enthusiasm customers show in feedback when I ask them to vote on new products. I post public updates on social media for these rather than updating everyone individually. Not all preorders require a minimum order number! It will be indicated in the listing if it is or not.
*Processing time may go over this average/estimate if there is an issue with your address, a fraud risk flag on your order, I become ill/injured or need to visit a hospital/ER due to my health conditions, if something goes wrong while packing (i.e. running out of tape, boxes, etc) or if something comes up with my family that interferes with running my shop. Just to name a few. Remember, I am one person running this shop. I do not have a team of workers and a warehouse and whatever else the big companies have, at my disposal.