Okay, so imagine you're in a class with a bunch of other kids. The teacher is at the front of the room, and all the students are sitting in rows behind desks.
Now, some of the students who are sitting in the very front row, closest to the teacher, are called "frontbenchers." These are the kids who are usually really smart, or who the teacher thinks are very responsible and trustworthy.
Being a frontbencher is kind of like being the teacher's pet, but it's a good thing because it means you get to be really close to the teacher and you might get to do some fun or important stuff in class, like helping the teacher pass out papers or answer questions.
In politics, "frontbencher" means something similar. It's a person who is part of a political party and who has an important position within that party. They are usually seen as very powerful or influential, and they get to sit in the front row of Parliament, which is where politicians go to debate and make decisions about things that affect the whole country.
So, being a frontbencher means you are an important and respected person within your party or in Parliament, kind of like being a teacher's pet, but for grown-ups.