You can run one monitor, keyboard and mouse via a KLM switch to several
computers and one switch moves you to and from the computers.

A KVM switch (with KVM being an abbreviation for Keyboard, Video or
Visual Display Unit, Mouse) is a hardware device that allows a user to
control multiple computers from a single keyboard, video monitor and
mouse. Although multiple computers are connected to the KVM, typically a
smaller number of computers can be controlled at any given time. Modern
devices have also added the ability to share USB devices and speakers
with multiple computers. Some KVM switches can also function in reverse
- that is, a single PC can be connected to multiple monitors, keyboards,
and mice. While not as common as the former, this configuration is
useful when the operator wants to access a single computer from two or
more (usually close) locations - for example, a public kiosk machine
that also has a staff maintenance interface behind the counter, or a
home office computer that doubles as a home theater PC.