I know that L$(V_1, V_2)$ denotes a linear transformation from $V_1$ to $V_2$.
What does $L(V)$ denote.
My guess would be that it denotes the homomorphism from $V$ to $V$ but I'm not sure.
First $L(V_1,V_2)$ denotes the space of all linear transformations from $V_1$ into $V_2$. So $L(V)$ denotes all the linear transformations from $V$ to $V$.