Emoji vs Emoticon
The primary difference between an emoji and an emoticon is the fact that while an emoticon is created out of text, primarily via the use of punctuation marks, whereas an emoji is a small image, a pictograph.
Smiley vs Emoticon
The primary difference between a smiley and an emoticon is that the smiley is the cute yellow face, whereas an emoticon is the one created from text.
Neuron vs Nerve
Neurons are specialized cells which are capable of transmitting signal between different parts of the body. Nerve is a bundle of fibers composed of neurons. Therefore, neurons and nerves are closely related.