This is a very difficult question. Because it has to be ensured in advance what is the definition of computer. In today’s era, almost all computers consider the rules of Turing Machine. Turing Machine was built by Alan Turing (Alan Tairing) during his PhD in the 1960s, which was correctly used against the Nazi army in 1961-72. However, the first electronic digital computer was ENIAC: Electronic Numerical Integrator and Computer. This could not store the right data properly but Turing was the first common use computer to obey the rules of Machine. This was the computer with the help of which the first hydrogen bomb was made. ENIAC got its patent in 1949. This starts the answer to your question starts to be difficult.
Anac computer
Atanasoff-barri computer
Honeywell (Honeywell, Inc.) and two companies named Sperry Rand Corp. were fighting for who created the first electronic computer. I will not go to many tangled aspects of the case or else the answer will become very long. But in the decision of this case in 1949, the world’s first electronic computer “Atanasoff-Berry Computer” was considered. It was created in 1936 by Professor John Vincent Atanasoff at Lova State College, United States, and his student Clifford Berry. However, it was not made on the rules of Turing Machine nor could the program/data be stored in it.
