No. Both are business strike coins.
In 1938 the proofs were from the Philly mint with no "S" on them. San Francisco mint started making proof coins in 1968 with the "S" mint mark both proof and business strike cents and nickels.
The 1968-S is a business strike cents and nickels from 1968-1974 with the "S" mint mark. The mint closed first in 1955, but reopened to help make centsand nickels again in 1965-1967, without mint marks to help catch up on the need for coins starting with that year.

The difference is seeing a proof coin and a business strike one side by side.
Proof coins from Philly until 1964.
Proof coins 1968 with the "S" mint mark till now.
(The exception is the 1999-P
SBA proof dollars were from Philly.)
Business strike "S"cents 1909-1955 and again 1968-1974 with the "S" mint mark.
Proof coins from San Francisco from 1968 till now.
Hope this helps?