Early Internet is before the Web was its main thing.

Early Web is before most netizens (remember that?) had ever heard or seen the term "blog", and much of the web was folks' "home pages" on whatever weird topic they were interested in (some were effectively "blogging", but that wasn't a term yet—"web log" might see limited use). This was the Nerd Web.

Mid-period is from the rise of "blog" to the rise of the smartphone, Google capitulating in the never-ending war on spammers and ruining itself instead, and Facebook coming about. Roughly '08 would be the end of this period. Call this the Macromedia Flash Web, perhaps.

Everything since that is the Late, or Hellscape, Web, an age dominated to an extreme degree by spam, scams, ads, astroturfing, and absolute insanity becoming normalized and spilling over into real life. This is the part that made it clear we'd have been better off never inventing any of this.