Turning device on remotely.

Are there ways to turn a device on remotely using a button or sensor?

Yes it is possible but it depends on how and what you want to turn on and off.
You can use an arduino with ethernet / bluetooth / IR / RFID or switch button and relay / relays.
Or you can use sensors like PIR / radar / temperature / humidity, etc. and relay / relays.
Can you give more details about what you want to do?

You need to be clear exactly what you mean by "turn on".

Think of a TV. If you switch the power on at the wall you are turning on the TV since it was completely dead until you supplied power. On the other hand if you use a 'remote' to turn the TV on it was in fact never completely off. It may have been in a low power sleeping mode but some part of it was active and looking for a 'wake' signal.

the distance you need for "remotely" greatly matters. the easiest - IMHO - is IR with a remote. most arduino kits sell those, or can buy very cheap. examples on how to use in the Adruino UI, and frankly - it just works well.

the rub - its very short range - like within a few meters. also, I've found the remotes to be "hobby grade" meaning maybe not the 100% expected output youd like.

be more specific, get more specific answers.

So basically I want to have a button or sensor turn the device on. The device and sensor will be about a meter apart. Like the device will only be on when the button is pressed or if there is something on top of the sensor. And device turns off if not.

jamesjamesz8:
So basically I want to have a button or sensor turn the device on.

It will be much easier to give useful advice if you tell us what this mysterious device actually is.

...R

jamesjamesz8:
So basically I want to have a button or sensor turn the device on. The device and sensor will be about a meter apart. Like the device will only be on when the button is pressed or if there is something on top of the sensor. And device turns off if not.

You still have not said if "off" means the device is to be totally without power or in some standby mode. If you mean totally without power then the button/sensor needs to operate a relay to cut or restore power to the device.

jamesjamesz8:
So basically I want to have a button or sensor turn the device on. The device and sensor will be about a meter apart. Like the device will only be on when the button is pressed or if there is something on top of the sensor. And device turns off if not.

What kind of button? Momentary or on/off?
What sensor?
What device?
How to turn on?
How to communicate over that meter?
What device to read the sensor and the button and to do the on/off switching?

Yes of course

MichaelEvans:
Yes of course

To which of the many questions that were asked, does this answer belong?

Considering that it was not OP but another rather new contributor (second post) I think it's answering the original question. And it's a perfectly correct, albeit rather useless answer.