What is an Optocoupler, optical coupler, power supply, output voltage, isolation voltage

 PS2501 Series Single Channel 80 Vce 5000 Vrms SMT Photocoupler - DIP-4

https://www.futureelectronics.com/p/semiconductors--optoelectronics--isolation-components-optocouplers/ps2501l-1-f3-a-renesas-1397785