Okay kiddo, so Russia and United Kingdom are like two grown-up countries who sometimes have disagreements and sometimes get along just fine.
You know how sometimes you and your friends might not agree on what game to play or what toy to share? That's kinda like what happens between Russia and United Kingdom, except on a much bigger scale.
Sometimes they disagree about big things like politics or war, and sometimes they disagree about little things like who gets to fish in a certain area of the ocean.
But even though they might have some disagreements, they also have some things in common. For example, they both like to play soccer and they both enjoy drinking tea!
It's kind of like when you and your friends might argue but still be friends in the end. Does that help explain it?