What connection means

In the absence of the tribe, people turn to substitute communities that may not sustain them - Sebastian Junger
At its core, this quote means that our fundamental human need for a close-knit, interdependent group is so strong that if we don't have one, we'll desperately try to fill that void with whatever's available, even if those replacements are ultimately hollow and unsatisfying.

What loneliness means

The modern world has greatly diminished our sense of belonging and purpose, leaving many to search for community in all the wrong places - Sebastian Junger
At its core, this quote means that our contemporary, individualistic society has fractured the deep, tribal connections humans naturally crave, and our attempts to rebuild that sense of community are often misguided and ultimately unsatisfying.