Specifically, the 8 pro has a 5x telephoto 48mp sensor that the base model lacks, a 48MP wide angle sensor compared to 12MP on the base model, a thermometer the base model lacks, 12GB of ram vs 8 on the base model, and a slightly larger and brighter display and slightly larger battery (though the gain in battery is probably roughly offset by the increased power draw of the screen). I believe those are the only hardware difference.
Specifically, the 8 pro has a 5x telephoto 48mp sensor that the base model lacks, a 48MP wide angle sensor compared to 12MP on the base model, a thermometer the base model lacks, 12GB of ram vs 8 on the base model, and a slightly larger and brighter display and slightly larger battery (though the gain in battery is probably roughly offset by the increased power draw of the screen). I believe those are the only hardware difference.
Source: https://www.phonearena.com/reviews/Google-Pixel-8-Pro-vs-Pixel-8-Google-is-about-to-reap-the-harvest_id5921