I thought there was a list around here that had something like what you were looking for.
Your Crown 4 is a sub-ohm tank. It uses a factory made coil. It may have an RBA which is a Re-buildable atomizer. It works just like your factory coils except you build the wire and wick it and it is reusable.
From there the list grows
RTA-re-buildable tank atomizer. It does not take factory coils. It has a deck that you build coils for and wick with cotton*. The coils are reusable. When your coils gunk up or if it is time for a cotton change you dry burn the coils and clean them with water, wire brush and then rewick them. The coils are at the bottom of the tank.
RDA-re-buildable dripping atomizer. It has no tank but a juice well instead. You build and install coils and wick it with cotton. You can take the top cap off and drip onto your coils or drip juice straight down the drip tip. These coils are reusable as well just like the RTA. RDAs are know for flavor because the coils are right there at your lips, opposed to an RTA where the vapor has to travel up a chimney.
RDTA-re-buildable dripping tank atomizer. In my opinion this is an outdated device, especially with the popularity of squonkers. Like the RTA and RDA, the RDTA uses coils you build and are wicked with cotton. The tanks sits below the coils instead of on top. This offers RDA flavor without having to drip every few hits because your cotton wicks hang down in the tank.
RDSA-re-buidable dripping squonk atomizer. It is an RDA with a 510 pin that has a hole in it. Works like an RDA as far as coils and wicking, it has a refillable bottle that you fill and squeeze. The juice travels though the squonk pin and saturates your cotton. Many describe it as “dripping upside down”.
Then there a few odd ones out there. Wotofo makes a RDTSA. It has a tank on the bottom like an RDTA but has a squonk pin,
RDAs and RDSAs are super simple to build on and wick. More so than an RDTAs.
RDAs are very popular because of flavor**. But it’s a pain to drip if you are active or driving down the road. The RTA, RDTA, RDSA and squonk mods alleviate the dripping issue.
*I used cotton because it is the most used wick material. There is also silica, rayon, and hemp.
**This is all subjective because there are many that believe that RTAs are so far advanced that the flavor is on par with RDAs. I don’t agree but that is simply my opinion. Whatever keeps people from smoking is the goal. I don’t judge. Whatever works for you.