Gigant wardens first appeared in Lufdurus which is, you could say, their birthplace before they spread around all of Bauleura, the only continent where you will find them. As their name says, they are a special soldier unit that almost every Bauleurian country has and that deal with Gigants - enormous, gigantous animals/creatures that can become as big as mountains, making them a threat to any cities they get close to, even if they do not even notice it and just move along. There have been lots of cities that were heavily damaged by them, either through direct attacks or just trampling through them.
Gigant wardens are there to protect cities from Gigants by driving them away since killing them would be too heavy on a country's resources and also because they are extremely difficult to kill, so it is much easier to just change their direction or even attack them enough to make them retreat. Of course, Gigants do not always appear but wardens are still stationed in every big city and able to quickly move to smaller ones.
They have their own unique training that mostly involves climbing and other ways to get up a Gigant and tactics on how to drive them away. Biology is an important subject as well since Gigants can be from different families and as such there are different types of them out there. Wardens even learn to camp on moving terrain, meaning on top of Gigants, because some of them are so big that it can take longer to find their weak spots or even get up. Their gear consists of easy to transport artillery, weapons designed to be used in unusual situations, like climbing up a Gigant and being attacked by a smaller bird-creature (or even creatures or Non-Eophrims living on top of Gigants), climbing gear, parachutes and other useful items. They try to use flying vehicles if they can but do not completely rely on them.
Just driving a Gigant away is not enough. The wardens usually make sure that the Gigant completely changes its course and does not come back, either by driving it far enough away if it was attacking or routing it so that it still reaches its destination if it was just passing through. After they have been driven away, the wardens usually look around on top of the Gigant and see if they can find scales, fur or other material they can harvest from them, so they can sell these resources or give them to their crafters.
Gigant wardens are important for Bauleurian cities and doing an extremely dangerous job to keep their people save but they are appreciated and many Bauleurians treat them like heroes. People from other continents are glad they do not have to deal with Gigants and probably never even heard of the wardens but tourists still like to visit their barracks and hear their stories.