The meaning of delta U

[Nick Kraemer 2J]

Hi!
I'm still confused about what the internal energy is or the change in internal energy and how that's different from the specific heat capacity.

[MaxReines1A]

The internal energy of a system (U) is all the energy held in all of the atoms within the system. Delta-U describes the change in internal energy over a period of time. While heat capacity is related to internal energy, it describes a specific system's ability to absorb heat. When the same amount of heat is added, two different systems may respond in different ways; their final temperatures may not be the same. This is the result of a difference in heat capacities.

[Howard Chu 1H]

The meaning of delta U is the change in internal energy of a system which is equal to the sum of the change in enthalpy plus pressure delta V.

[Nikki Ma 3B]

while delta u is the change (final - initial) of the internal energy, heat capacity refers to the amount of heat energy needed to raise the temperature by one unit

[Jonathan_Yu_2C]

Delta u is the change in internal energy, and heat capacity is the heat to raise the temperature by one degree