Okay kiddo, so you know how sometimes you see pretty designs inside glass objects like vases or bowls? Murrine is kind of like making those designs, but on a smaller scale.
It starts with taking different colors of glass and melting them together into a big cylinder shape. Then, it's cooled down and cut into small pieces that each have a little bit of all the colors.
Next, those little pieces are arranged in a pattern on a flat surface like a table. The pattern is covered with another layer of clear glass, so it looks like the little pieces are trapped inside.
Finally, the whole thing is heated up again and made into whatever object it's going to be, like a paperweight or a pendant for a necklace.
So basically, murrine is a fancy way of making glass objects look super cool and colorful!