This Buddhist concept ultimately means: we are all in this together. We are all responsible. Everything matters. It can be parsed and simplified as, to quote the Buddhist Nun Pema Chodron has put it: [There is] No Escape.
Donald Trump held one of his MAGA superspreader rallies in Georgia last night. I was sleeping in PoznaĆ. Somehow there are connections. We may not see them; we may never see them. But somehow each of us bears some nuanced responsibility for Trump, for Brexit, for the Law and Justice party in Poland. There isn't anything that escapes being connected to everything else, and there isn't anything that escapes being connected to us.
The term is actually dependent origination, sometimes set out as dependent co-origination. Co-dependent Origination is just a tip of the hat to co-dependence.