Okay kiddo, imagine you are playing with a toy and you want to go from one side of the room to the other. But instead of just walking straight across, there is a big wall in the middle and you have to go around it. That's kind of like the Strait of Kerch.
The Strait of Kerch is a narrow strip of water that connects two big bodies of water - the Black Sea and the Sea of Azov. It's located between Russia and Crimea, which is a peninsula that used to belong to Ukraine but is now controlled by Russia.
Now, the reason this strait is important is because it's the only way for ships to get from the Black Sea to the Sea of Azov. And that's important because there are a lot of ports and cities along the Sea of Azov that need to get supplies and goods by ship.
But, just like the wall in your room, there are some obstacles that make it a bit tricky to use the Strait of Kerch. One of these obstacles is a big underwater ridge called the Kerch Peninsula. This ridge sticks up from the ocean floor and makes it hard for big ships to pass through the strait.
Another obstacle is that Russia has built a bridge over the strait which has caused some tension with Ukraine. Ukraine wanted to keep control of the strait and said that the Russian bridge was illegal. But Russia didn't listen and built the bridge anyway.
So, as you can see, the Strait of Kerch is an important piece of water that connects two big seas. But it's also a place where there are some obstacles and tensions between different countries.