Question

why computer invented second time

Answer 1

The first computer was made to crack the encrypted communications of Germany (lookup Enigma in an encyclopedia) during the 2nd world war.

After that computers were made to perform calculations to a higher precision and at a higher speed than humans were capable of.

Following that, computers have been steadily improved to solve all kinds of problems, starting with business tasks like accounting and taxes, then continuing on to customer and order management, billing, etc.

When computers finally could be made small enough that workers could have one each, use cases like document editing, business management, and others popped up.

Finally, computers became capable of graphics and media, resulting in most of the usage we observe today (of course powered by networking, which is another topic).