I think of nodes in a lightning transaction like mini banks in a Venmo, Cashapp, or Zelle transaction. Basically, when I send you money, our banks (our nodes) agree to change the amount of credit owed to each other by the amount I send you. Channels are just a miniature version of the credit owed agreed upon number between banks, and in a lightning transaction, there are multiple nodes, each with a single channel in between. I’ll leave it at that.