The maximal solvable normal subgroup of $G$ is called the radical subgroup of $G$, and it is denoted by $Rad(G)$ of $R(G)$.
Question: Is the quotient group $G/R(G)$ been classified (i.e., it always has some well-known group structure)? Here it is mentioned that $G/R(G)$ is semi-simple. What does that mean?
Edit: I thought that semi-simple groups are the product of simple groups. Thus I got confused with this.