High voltage control without realys

Hello, I have a doubt that i couldn't find an answer to anywere...

So, we can use relays to control high voltage devices with Arduino,
but with this method we can just turn them on or off.
I would like to know what can we use to make those devices work at, lets say, 30% od 70% of their intensity (instead of 0% or 100%).

As an example, I would like to change light bulbs (60W) intensity with an Arduino, controling it glow more or less, depending on some condition. I would like to know how this can be achieved.

Thank you in advance.

A. a simple resistor, transistor, diode(kick back, if lamp is little inductive) will achieve that provided the lamp is 'dimmable' and it's a DC one

one of the PWM pin of your Arduino will do the 'on/off, in duty cycle manner' to your transistor

B. or you could deploy a triac driver board (forgot the model number but i used one before, it worked)

or you could build your own. and that's for a dimmable AC lamp