From Destinypedia, the Destiny wiki
Servitors are spheres, built of a dark metal in a shape reminiscent of the Great Machine. Most have a central purple glowing eye, and rarely possess any other distinguishing features or liveries that link it to their House. They are capable of flight, and hover as their main method of travel, however, this seems to be a function of their shell, as the cores of Servitors, once stripped of their armor, appear incapable of movement, yet still react to their surroundings. The desperation of modern Fallen Houses can be seen in the state they keep their Servitors, as the House of Dusk and House of Salvation have reduced the amount of plating dedicated to their protection, leaving more of the Servitor's circuitry exposed, however, in the case of House of Salvation, this is intentional, degrading their appearance as a manifestation of their House's hatred for the Great Machine.
While they support Fallen in battle, shielding allies, facilitating communications and transmitting tactical data between one another, the Servitors' main function is to process matter and energy into Ether for the Fallen's sustenance. Besides that, they also offer technological acuity as navigation aids Ketches, and possibly Skiffs. Some specialized Servitors also serve as personal support and as pilots for High-ranking Fallen.
Servitors possess extremely sophisticated and valuable technology, such as Servitor plugs, filters and Ether circulators, to the extent that their artificial intelligence gives them a limited degree of sentience. Despite this, they are vulnerable to being overloaded and shorting out. Not only do they generate Ether, they also hold it, until they are drained of it. The communication network a Servitor is connected to can be accessed by a Ghost, through which those connected to the network becoming locatable.
There are more powerful Servitors known as High Servitors, capable of jamming signals. Above High Servitors are Prime Servitors, the largest known form of Servitor. Prime Servitors are potentially integral to Fallen space travel, offer logistical support, and the Fallen worship and revere them as if they were gods, presumably given their symbolic relevance to Great Machine, as well as the fact that they produce major tons of Ether and are an integral part of the leadership of most Houses, alongside an Archon and a Kell. For these reasons, almost every Fallen House has their own Prime Servitor; if it is destroyed, the House becomes extremely vulnerable. Certain Servitors function as pilots, and are called Pilot Servitors.
Servitors' primary usage in combat is to support accompanying Fallen units by emitting a purple glow, giving them a nourishing boost. To evade incoming attacks and flank their targets, Servitors will occasionally teleport short distances. They are shown to be a resilient threat and are capable of firing powerful blasts of Void energy from their eye, which is also a weak spot. They frequently try to protect this weak spot when in combat, making them difficult targets. In Destiny 2, Servitors have switched their nourishing boost with the ability to generate tethers toward nearby Fallen units, granting them complete immunity to incoming damage. They also gain Void shields in high difficulty activities.
Servitors encountered as Elites or Majors have increased health and stronger damage resistance compared to Minor variants, but usually do not differ in looks. Ultra or larger Servitors gain a powerful melee attack, releasing a health draining vortex from their eye whenever a foe gets up close.
List of appearances