hello everyone .can anyone help me and explain to me this codes for real time ploting????please????

arduino=serial('COM10','BaudRate',9600);

fopen(arduino);

CM(1)=0;

time(1)=0;

i=1;

tic;

while (toc<=100)

CM(2)=fscanf(arduino,'%f');

time(2)=toc;

figure(1);

grid on;

axis([toc-10, toc+10, 0, 35])

h(i)=plot(time,CM,'b','LineWidth',5);

hold on

CM(1)=CM(2);

time(1)=time(2);

if(i >= 300)

delete(h(i-299));

end

i=i+1;

end

fclose(arduino); % end communication with arduino