Most Helpful Guy
No it is not. Fun fact the TOR browser was devoted by the military. No it is not illegal to access the deep web. The popular browsers censor some stuff from the internet. However if you like buy drugs while your on the deep web or something like that, yeah that's illegal. But there is a lot of information on the internet and some can be found in the deep web1
Most Helpful Girl
Deep web are webpages that are not accessible via google search or other pages. You have to know the link to get to them, they are not illegal.
Dark web you have to use TOR to access and it is not illegal, but it is often used for illegal activities (Drug and Sex trafficking), but whistleblowers have used it too.1