Home Page is "what", as in what the site is about.
About, previously "About us", but the "us" got dropped along the way, is meant to describe the "who, ie: the person, persons, team, organization or company that created the site. As well as answering where, when and, why.
At least that is how I've always structured my sites.
Sites structures have also evolved over time, nowadays the home pages are often built such that the various sections are included as infinite scrolls on one long page.
As to home page as splash screen approach
the corporate logo, maybe an image or two and a tagline being present
IMO this makes a lot of sense, you should be able to provide a succinct description of what your website offers, an "elevator pitch" of sorts. If the user want more info it's a click, swipe or scroll away. Bold visuals, and a brief pitch.
IME Google typically doesn't send much traffic to your home page, it sends users to product or info pages, where they can find the answers to their queries.