What does "TEL of Tor" means ?
T.E.L. - Transporter-Erector-Launcher....
An All-purpose vehicle that not only carries the missile system around but can raise into the launch position and launch it at the target on short notice.
Usually carries the launch crew on board.
With the older liquid-fueled missiles it would have accompanying fueling trucks, and the missile would have to be fuel just prior to launch - a lengthy and dangerous operation, during which the whole system and crew were very vulnerable to attack.
When storable liquid propellants and solid propellants were developed, there was no longer a need for the fuel trucks, greatly enhancing response time, concealment and system survivability.
Good examples are the Chinese copies of Soviet-era launchers for the DF-15, DF-21 (based on the MAZ transporter truck) and the indigenous DF-31/A missile launchers that parade during major PRC anniversaries.
In addition to ballistic missile systems (SSM's) TELs are also used for Surface-to-Air Missile systems (SAMs) like the Tor you mentioned.
The smaller, short-ranged SAM TELs usually have tracking and engagement radars (as well as electro-optical or IR systems) on board - to control the engagement, and sometimes also the search radars attached - like the Tor/Tor M1.
Larger SAMs like the S200 have specialized search, track and engagement radars mounted on separate vehicles.
