What is the difference between real rubber and fake rubber?

Could you please elaborate on the distinction between genuine rubber and its synthetic counterpart? I'm particularly interested in understanding the material properties, durability, and potential applications of each type. Additionally, I'm wondering if there are any environmental considerations or safety implications associated with the use of fake rubber. Could you also discuss how to identify the authenticity of rubber products? I'm keen to gain a comprehensive understanding of the differences between these two types of rubber.