Difference between char* and char[]

From K& R

char amessage[] = "Hello Word"; // This is an array
char*pmessage = "Hello World"; // This is a pointer


This is immediately visible in strtok function in C, which breaks the sentence into words

if I take something in this direction
char*origstring = "abc,def,ghi,jkl";
char* sep = ",";

char*delimstring = strtok(origstring,sep);
This would result in an error

Could be overcomed by the following solution
char origstring[] = "abc,def,ghi,jkl";
char* sep = ",";

char*delimstring = strtok(origstring,sep);


-Kalyan