Business service management means making sure that the things a company does for its customers are working really well. It's like making sure that all the parts of a big machine are working properly, so that the machine can do its job really well.
For example, let's say a company makes and sells computers. If the computers have problems, customers might not be happy and might not buy more computers in the future. So, the company needs to make sure that the computers are working great all the time. This is where business service management comes in.
People who work in business service management make sure that all the different parts of the company are working together to make sure the computers run well. They might check the quality of the parts that go into the computer, make sure the computer software is working correctly, and even make sure that the people who are fixing the computers when things go wrong know what they're doing.
In short, business service management is like a helpful machine doctor, making sure all the parts of the company work together properly to give customers the best products and services possible.