Comment by cowlevel
15 hours ago
geometric/polynomial: x^2, x^3, etc
exponential: 2^x, 3^x, etc
Everything in the second group eventually grows faster than everything in the first group, no matter how small and big you make the fixed numbers, so they are two different classes.
Geometric is exponential; I goofed above. Geometric and exponential are sometimes used interchangeably, but sometimes people use geometric to refer to discrete intervals and exponential to refer to continuous functions.