Ash Ketchum in Indigo League
Some people think Ash and Red are the same. But that is NOT true! In this, the comparisons will say the differences, and the similarities.
Gym Battles Red
It has been a long time since I read the Pokemon Manga, but I can remember Red did win most of the Badges in Kanto. If I remember correctly,
You probably remember that Ash only won the battle against Lt. Surge! The other of the first 5 battles, the Gym Leaders gave him the badge for assistance (Like in Pokemon Scent-sation), rather than actually winning. And the battle in "Battle For The Badge", where Ash battled Jessie (While James & Meowth watched, and tried to cheat) shouldn't have counted! He should have had to battle Giovanni!
Red is a silent Trainer (As seen in HG/SS), in fact, he doesn't talk at all! Not much else is known about him, except he wanted to be the greatest Trainer. Also, in R/B, he only answers yes or no to any questions.
A Trainer with the same goal as Red, Ash was a stubborn Trainer in the beginning, but dedication to his goal paid off, with him entering the Indigo League.
Again, I haven't read the Pokemon Manga in a long time, so I don't remember all the PKMN Red caught. But here are some:
Starter: Can't remember (Bulbasaur maybe?)
Gyarados (Given to him from Misty)
and some others.
With Prof. Oak
Also, the two have had some other differences that aren't above! Here are some more.
Red actually defeated Team Rocket, Ash only has battled Jessie/James and Butch/Cassidy.
Ash had caught a Shiny Pokemon, Red hadn't (I think).
Red's Charizard (As seen in Super Smash Bros. Brawl) actually does things! Unlike Ash's Charizard, who sleeps through a battle (Like in the Cinnabar Gym Battle and Indigo League Vs. Ritchie).
Red has caught more Pokemon, and his Pikachu is much weaker than Ash's.
Red in Leaf Green/Fire Red and Heart Gold/Soul Silver