Final answer:
Cell to cell contact occurs when cells physically touch each other, while secreted signaling molecules are released by one cell and travel to target cells.
Step-by-step explanation:
Cell to cell contact and secreted signaling molecules are two ways that cells communicate with each other.
Cell to cell contact occurs when the surface of one cell comes into direct physical contact with another cell.
This can happen through tight junctions, adherens junctions, or gap junctions.
On the other hand, secreted signaling molecules are released by one cell and travel through extracellular fluid to reach target cells.
These molecules can act as hormones, neurotransmitters, or growth factors, among others.