The axon is the single long process of the cell body. Dendrites are the multiple cell processes which branch extensively immediately after taking root from the soma. (It is wrong to define axon as the process carrying impulses away from the cell body. For example, the peripheral processes of the dorsal root ganglion are axons that carry impulses towards the cell body.) Axons conduct action potentials.
Dendrites usually do not produce action potentials: they mostly conduct graded potentials.