What does the bypass function do in a UPS emergency power supply system?

Hello, I have a question about the BYPASS in UPS, what is it for. Please explain it to the peasant reason

The bypass is the primary power supply (from the power grid) located in the upkeep, but after the power grid has been cut off, the connected ups supply all the circuits connected to it, except for its own bypass outputs ...

that is, the bypass is such a socket without holding the voltage, connected straight from the network.

You understand well. Most often this is used to connect the next UPS when there are more than one.

There are 2 types of BYPASS in larger UPSs:
- internal in the UPS, it is used to protect the UPS against overload, the internal circuits of the UPS are live
- external - bypassing the entire UPS, after manually turning it on, UPS maintenance can be performed

In both cases of BYPASS, the receivers are connected directly to the "city", so they are not protected against loss.

The name itself suggests that bypass is "bypass".
In guaranteed power supply systems, BYPASS occurs
internal and external - service option.
The internal BYPASS is a kind of protection of the UPS against
overload and "dropping" of power supply to receivers - in case of overload
switches the network directly to the output - apart from the UPS processing path, it is most common in on-line technology, less often in line-interactive,
and secures the power supply of devices in the event of a UPS failure - supplies power
directly from the network. Changeover is automatic and controlled
by UPS.
The external BYPASS is most often used to "bypass" the UPS and disconnect it
from power supply during service works - manual BYPASS, service BYPASS.
An output socket not "protected" is not a BYPASS!

SLAL