> In Star Trek all species are at an historically identical technology level. Even the Borg. There are no space faring civilisations more than 500 years ahead or behind,
There are several instances where starfleet finds species that are vastly more technically advanced. Q are a notable example. There isn't usually much interaction with them though, sometimes the humans are told outright that they just aren't ready yet.
There are also many instances where they find species more than 500 years behind. As a matter of policy they try not to interfere with those species, but they do research and monitor them sometimes. They are species too far behind technologically to have developed warp technology, but far enough advanced to make it into space on their own and species who weren't advanced enough to make it into space on their own but ended up there anyway. Ornarans started off being a technically advanced pre-warp species, but all that knowledge was lost leaving them flying around in ships they didn't understand enough to make even basic repairs.
There are several instances where starfleet finds species that are vastly more technically advanced. Q are a notable example. There isn't usually much interaction with them though, sometimes the humans are told outright that they just aren't ready yet.
There are also many instances where they find species more than 500 years behind. As a matter of policy they try not to interfere with those species, but they do research and monitor them sometimes. They are species too far behind technologically to have developed warp technology, but far enough advanced to make it into space on their own and species who weren't advanced enough to make it into space on their own but ended up there anyway. Ornarans started off being a technically advanced pre-warp species, but all that knowledge was lost leaving them flying around in ships they didn't understand enough to make even basic repairs.