The good kind is when you can catch up and it's like nothing has changed, in the sense, there's still a bond, not that your lives haven't changed.
Friendships/relationships take work, and maintenance, and some maintain better than others, I don't always reach out, but I always reach back, and I accept every invite, because people do move in different directions, so if my homies invite me to their kids party, that's one of the only common points we can connect. So I go.
Friendships also ebb and flow, and get new life all the time. I do have two friends that I grew up on the same street with, and we never fell out or fell off, just drifted and drifted, for awhile, I thought it was me. Like I wasn't good enough. And I was resentful. And I slowly realized, it was just who they were. They didn't value that relationship the way I did. But, I still can hit them up for a quick text, but again, it should be mutual, not even, but mutual.
also, a note that, there are friendships that just aren't maintained via digital or phone communication, but IF you were to see each other, you would be hugging and laughing, and that's part of it all too. That's how I feel about my two homies.