Overdrive and distortion pedals can also be called gain pedals, dirt, or crunch pedals. These pedals can add grit and volume to your guitar's tone. It doesn't matter if it's called gain or dirt, the concept is the same. You might get different answers depending on who you ask about the difference between distortion or overdrive. It is difficult to explain the differences between them in words.
My experience with overdrive is that it has a hollower sound, less sustain, and a more "bluesy". There are many overdrive pedals on the market, but Ibanez's Tube Screamer is the most famous. Today, there are many companies that make tube screamer pedals. For more information on boutique, overdrive visit https://www.mochaearth.com.au/collections/overdrive.
Tube Screamers were used by Stevie Ray Vaughan throughout his career. This is partly due to the immense influence he has had on so many people. You will often see a Tube Screamer variation on every guitarist's pedalboard.
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If you insist on a description, Distortion is a crunchy, gritty type of sound with lots of sustain. This is the sound that a lot of classic rock bands use, as well as heavy and metal bands. A lot of guitar amps can produce a rich, fat distortion, so a distortion pedal is not necessary. There are many amps that produce very little distortion. A distortion pedal can transform the amp's clean sound into a rocking sound.
Sometimes the difference between distortion pedals versus overdrive pedals is subtle. My distortion pedals can sound almost like an overdrive pedal by decreasing the gain and adjusting the tone knob. However, turning the knobs in the opposite direction would produce a typical distortion sound with a high gain on most distortion pedals.