What's the difference between isothermal and adiabatic processes?

[AxiomOfChoice]

What's the difference?

 

[Borek]

What are definitions?

 

[AxiomOfChoice]

Well, from what I can tell, saying a transformation of a system is isothermal indicates no net change in the internal energy of the system, implying $\Delta U = 0$, implying $W = -\Delta Q$. Adiabatic changes only entail no heat being added or subtracted to or from the system. So there isn't necessarily a zero change in U, since the system can do work, or have work done on it.

Is everything I've said right?

 

[Dickfore]

http://www.merriam-webster.com/dictionary/isothermal"

http://www.merriam-webster.com/dictionary/adiabatic?show=0&t=1283871003"

Also:

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/firlaw.html"

See if you can check whether what you said is correct.