Salamander Reconnaissance Tank
The Salamander Reconnaissance Tank is an Imperial Guard fast light tank based on the Chimera chassis. Named after the Salamanders in universe, seemingly in a ploy by GW to confuse their players as much as possible.
Salamander Command Vehicle
Not to be confused with the SCV unit from StarCraft.
The Salamander Command Vehicle is a transport and command-and-control vehicle used by leaders of armored reconnaissance units. They're not meant to get into a fight; though they are armored enough in the front to be invulnerable to most infantry weapons, they are not so well protected from the sides and rear, and they are only armed with a heavy flamer and a heavy bolter, though they can also mount a heavy stubber or storm bolter (which can itself be fitted to an anti-aircraft mount, to chase away any flyers that get too close -- though given how wimpy these weapons are, most flyers won't feel threatened by them) and a hunter-killer missile for a little extra punch.
The primary utility of the Salamander Command Vehicle is not on the front line, but in the middle or rear; its improved communications equipment allow orders to be transmitted further and more clearly and lets the commander guide their troops more carefully, while the advanced detection systems help them spot infiltrators. For these reasons, the Salamander Command Vehicle is often requested even by officers who do not lead reconnaissance units. Notably, Ciaphas Cain often uses takes Salamander into battle, though Jurgen's driving often makes the trip more dangerous than the battle itself.
Salamander Scout Vehicle
The Salamander Scout Vehicle is the primary reconnaissance vehicle of the Imperial Guard Armored Battle Group Regiments. Though no match for a tank, it is fast and capable of leaving any dangerous situation quickly and, unlike the Sentinel scout, capable of protracted engagements with the light vehicles of enemy scout units.
Salamander Scout Vehicle usually work in pairs for mutual protection, taking turns as one vehicle moves forward under the cover of the other, since they are most likely to be ambushed or encounter a strong enemy position. The open top and lack of turret make the choice of sending this vehicle into potential ambushes questionable at best, but efficiency have practicality have never really been a big consideration for the Administratum.
For major offensives when there are insufficient numbers of Salamander Scouts it is common to mix them with Armoured Fist Squads temporarily detached from their parent platoon or company. While an offensive unit by nature, Salamander Scouts like their Command cousins are also used for rear area policing and security duties, such as patrolling supply routes or guarding headquarters units, when operating on the defensive.
It packs an autocannon instead of a heavy flamer, for slightly better anti-armor performance, but is otherwise not any more resilient than the command variant.
Tabletop
The Salamander is no longer on Forgeworld's menu so if you want to use one it's time to break out the bits and get converting or scour Ebay.
In 8th Edition, the Salamander is moved to the Elites slot and performs a little differently. It's now a mobile source of improved hit rolls, granting +1 to hit to one vehicle within 6". Alongside the Trojan Support Vehicle, this is a babysitter for your deathstar (either a superheavy vehicle or just a Leman Russ stuffed to the gills with plasma) and a fine one at that.