What is the difference between ZKsync Lite and ZKsync era?

Can you please elaborate on the key differences between zksync Lite and ZKsync era? I'm particularly interested in understanding the technical advancements, scalability potential, and potential use cases that set these two apart. Additionally, how do they compare in terms of security, transaction speed, and gas fees? It would be helpful if you could provide a concise overview that highlights the most significant differences.