Atheist
An atheist, as defined by the Oxford dictionary, is someone who lacks belief in the existence of gods or deities. Atheism is not a belief system or a religion; it is simply the absence of belief in any gods. Atheists may come to this position through various means, such as skepticism, rational inquiry, or lack of evidence for the existence of gods. Simply stated, they do not believe that God exists. They may subscribe to any of the arguments previously presented or to a combination thereof. Regardless of the arguments they subscribe to, they cannot deny anything that is supported by clear evidence.
Agnostic
An agnostic, as defined by the Oxford dictionary, is someone who holds the view that the existence of gods or the supernatural is unknown, inherently unknowable, or that there is insufficient evidence to support either belief or disbelief in their existence. Agnosticism is often characterized by skepticism towards claims about the existence or non-existence of gods or the supernatural. Unlike atheists, who lack belief in gods, and theists, who believe in gods, agnostics take a more neutral stance regarding the existence of gods. Simply stated, they do not know whether God exists. These people are in a state of confusion. They require strong evidence to affirm their belief system.
Both of these aforementioned types of people have their similarities and differences. Both groups may have subscribed to various arguments. However, neither group can deny any scientific or historical phenomena that is supported by clear evidence.