In reply to yuri-panchul-samsung:
One small important distinction
logic a = 1; // is not exactly equivalent to
logic a;
initial a = 1;
Static variables get initialized once at time 0 before any initial or always processes have started.
logic a = 1;
logic b;
initial b = 1;
initial $display(a,,b);
The value of a displayed is guaranteed to be 1. The value of b displayed is indeterminate and could be 0 or 1.