How do Biotic implants work? What's the difference between them and Biotic Amps?
These can be further researched by looking up their respective entries in the codex. But on general principle, Biotic Implants are what allow organics to harness the ability of eezo nodes in their body, and utilize these growths well enough to generate mass effect fields. L2, L3, and so on Implants are what allow Humans to use biotics. Asari have this ability to control their eezo nodes naturally, and so, do not need implants.
Biotic Amps on the other hand are basically biotic mods. Through a port usually located on the back of one's neck, one can insert an amp and 'amplify' their biotic ability even further. Asari DO use amps. I am not sure if amps are required for other beings to use their biotics in tandem with an implant however. Basically, implants give you ability to manifest biotics, and amps makes your biotics more powerful.