Residential (Resi) proxies provide unlimited stable proxies which can be used on almost any site. However, resi proxies are slower than ISPs and ran on a data plan.
ISP proxies provide faster speeds and more stability than Residential proxies. However, ISPs are more likely to be banned on most sites (except the main ones: Footsites, Yeezy Supply, Shopify) Furthermore, ISPs can be used for any duration (until it expires) and it is more expensive than Resis since it is purchased in quantities rather than GBs.