It is important to keep in mind that both does not necessarily mean you are working both batteries equally. It can be operated mechanically by handle or can be operated by a motor.

How To Install A Battery Isolator In Your Conversion Van
What does an isolator switch do. This switch allows you to use one battery over another for running your boat while another battery may run electronics while the boat is not running. What do you mean by isolator. What do you mean by electrical isolation. Isolators are used to open a circuit under no load. Digital isolators use transformers or capacitors to magnetically or capacitively couple data across an isolation barrier compared to optocouplers that use light from leds. In electrical engineering a disconnector disconnect switch or isolator switch is used to ensure that an electrical circuit is completely de energized for service or maintenance.
Generally these are employed on circuit breaker both the ends thus the circuit breaker repair can be done easily without any risk. The isolator is a mechanical switch which isolates a part of the circuit from the system as when required. Isolator switches are used for opening an electrical circuit in the no load condition. A similar situation arises where typically a double pole switch is installed next to an immersion heater as shown in fig 3. A battery isolator typically is used in situations where multiple batteries are required and its primary purpose is to ensure that the failure of a single battery will not incapacitate an entire electrical system. Electrical isolators separate a part of the system from rest for safe maintenance works.
A battery isolator is a one way electrical battery that allows an electrical current to flow in one direction but not the other. Ability to switch off when a predetermined temperature has been reached if heat is detected from a fire the entire system will safely shut down. Where the duties of an isolator are to make andor break a circuit under load it is usually marked with a symbol to indicate its switching capability. Disconnectors can be operated either manually or automatically. It can be open or close to disconnect or join the two parts of circuit. Some battery switches have an area that says both.
Ability to shut down solar generation independent from the solar panels. It is not proposed to be opened while current flows through the line. An isolator or disconnector is a switching device which is used in the transmission and distribution substation to isolate the one part of electrical circuit from another temporarily. Ability to clearly indicate safe solar panel isolation via existing inverter. Transformers pulse current through a coil as shown in figure 1 to create a small localized magnetic field that induces current in another coil. In electrical engineering a disconnector disconnect switch or isolator switch is used to ensure that an electrical circuit is completely de energized for service or maintenance.
So the definition of isolator can be rewritten as an isolator is a manually operated mechanical switch which separates a part of the electrical power.