Types of Planters
Raised bed gardening is a technique used to separate ground plants like grasses from the fruits and vegetables that we want to grow. It also assists in keeping animals out from messing with your plants, though it won’t stop birds unless more measures are taken. (Mainly netting)

Raised beds are great for small communities or for those unversed in horticulture. You don’t have to go through calling up electric companies or phone companies or the state to dig through a place you thought might be great for a garden but ends up holding a power line, water line, or worst a sewer line. The downside of course is the cost of the material both container and soil. Treated wood works great, and is largely customizable to the plot you have especially if you are handy. Wood can be cut to suit your needs, however… Pre-made galvanized steel beds are cheaper but come at the conceptual cost of inflexibility. You can, of course, find things in the size that you want but if you want to expand, unlike taking apart some of your planks and adding to the planter, with steel you’ll likely just have to buy a new planter. Galvanized steel, however, can also come in many colors, though primarily earth tones. Plastic and vinyl planters also exist and support many more colors natively from purchase. If you’re the decorative type anyway though, we’d recommend a stronger material and then painting or coating the planter to your leisure. It will be noted that wooden planters may need to have the insides waterproofed, especially if you are looking to install an internal watering system. Cement board can also be used, though it could also do with waterproofing so it doesn’t grow any mosses, algae, or fungi on the surface since it is a slightly porous surface.
Types of Soils
While of course, we mentioned that it’s a downside in having to buy soil for a raised planter, it can also be a boon for how much control you have over what goes into it. With your native soil, you may do tests and end up finding that it is full of sand, silt, or clay. While things can still be grown out of those soils, they can make it difficult for you in the long term. Having all the water you put in run out, or rotting the roots of your plants from being sopping wet is counterproductive to going through the effort to get a raised bed. So if you have extra soil laying around that was planned to go in a bed, make sure that you know what you’re putting into it. Otherwise, most planter soils available at gardening or hardware stores should be suitable. A short text guide for measuring your soil can be found here.

How raised is a raised bed?
Some raised beds are connected to the ground while others can be fully detached from the ground. having a fully connected raised bed has some benefits in that certain subterranian animals like worms that can be beneficial to your plants may be able to wander into the bed, some worms are good some are bad, it depends on what you grow but generally they are helpful. Having the bed connected to the ground also technically attaches it to the water table which will restrict your drainage to the average of the rest of your soil though some can be diverted through the sides of the box. Some plants are going to want to be attached to the ground because their root systems want to go down deep into the soil, others can be placated into being in a floating soil box just fine.
Doing Drainage
Then there is drainage. A raised bed is one of the greatest sources of granular control for drainage. There are no unexpected water tables like underground because you are controlling where the water can lie at. `You can add rocks at the bottom for space to water to move through, you can drill in holes near the bottom for natural flow near the bottom. Fastening in a spigot is also an option if you suspect weather may flood your beds on occasion. There needs to be enough flow and space for a spigot to be effective and hopefully, if you do enough of the other methods you won’t need to do this in the first place. Holes for drainage need to be big enough not to plug when water flows through, but not so big that soil falls out of the holes. Even more related information can be found here, and here.
Watering systems
There are plenty of ways to autonomously water your plants from a raised bed. Misting systems on timers work of course but there are more ingenious ways to water your plants in a raised bed. The Sub Irrigation Planter system is an internal watering system that uses the stores the water you want to have for the plants at the bottom of the planter and is resistant to evaporation that would normally reduce the results you would see from misting or regular watering. The main drawback to this system is that it will occasionally need to be flushed in case there are water-soluble minerals or salt that can build up inside the piping. SIP system boxes are purchasable as is as well if you aren’t looking to build one yourself.