Right, let's have something for the uniform nerds.
The Swedish Royal Guards, (there are actually several units but let's stick to this one).
As you may tell from their helmets, riding boots and Mauser carbines, they are dragoons, light dragoons to be exact.
Interestingly the officer is armed with a pallask. A straight heavy cavalry sword. Light dragoons usually carried sabres.
Dragoons were initially mounted infantry armed with full length muskets.
The purpose was to ride up fast to where they were needed, dismount and engage the enemy.
A bit like modern airborne troops. I.e. highly mobile, but fairly few and without heavy support weapons, with the purpose of getting to a position and hold until relieved. Alternatively to fight a delaying action and mount and get away before cut off or overwhelmed.
The sabres at that point was predominantly a defensive weapon.
Later on dragoons evolved to become all-purpose-cavalry. Meaning they could perform every cavalry role, not as good as the more specialised cavalry, like hussars, lansers and cuirassiers, but still.
Eventually dragoons, which were in constant demand due to their versatillity, evolved into light and heavy dragoons.
The from Hollywood very famous US cavalry were actually de facto a mix of light and heavy dragoons. I.e. riding large and heavy horses, but being armed with light carbines. A typical politicians move, which meant that they often were too heavy to catch up with the more nimbly mounted natives and too lightly armed, which meant they were sometimes outgunned in several critical engagements.
The Congress actually considered raising dragoon regiments after the Civil War, but that was considered too expensive. Result: Infantry companies had to be mounted to fill in the gap.
Here we have the dragoons in full gala. Complete with the svejf/plume on their helmets. The plume was meant to resemble the mane of the horse, not
the tail. - Oh, no, no, no! (No buttheads here, please).
Notice the officer with the gorget in a chain around his neck.
Originally designed as a throat protection as a part of full armour, it evolved into a symbol of authority.