What is the differance between light and heavy infantry

[stevesarak]

Hi,

In Caesar’s writings he mentions heavy infantry a lot. What exactly was the difference between Republican heavy and light infantry, I’m assuming they must have worn different armor. Helm, lorica, gladius, pugio, pila, this is what I thought that all republican legionaries (not counting slingers) wore, but there must be a difference between light and heavy.

Can someone please shed some light on this?

Thanks