The perception
In general, the popular perception is that every book needs to be bought and read - if one wanted to read legally.
Evolution of sources of books
The obvious choice is to buy the books from the bookstore as and when they are released. Or, even many days, months and years after they are released. Physical bookstores did that always - this is the traditional way of buying and selling books and still remains the same.
Up came the Internet, the the evolution of buying books found a new way - the online stores. Within a short number of years, great booksellers as Amazon and Barnes & Noble established themselves as the leaders. You could now order book from home on the Internet and get them delivered easily. Talk of saving time and energy to grab the book!
To leverage the readers who look for books with a heavy discount and are prepared to (or had to, for whatever reason) wait till much after the book was published, up came half-price book shops. The reader who were late in buying the books (even if because the reader was not born when the book was written) started being happy. The age-old selling of cheaper-than-original book culture now formalized.
Smart online book sellers started having low-price book selling features in their online stores where a reader could sell another reader a used book. And they kept a commission. This again was the value-add of saved time and energy for the reader to get the book easily.
Then up came book digitization projects. Many books were digitized across various efforts around the world. But not all books could be fully provided online because of copyright issues.
All books belonging to the Classic Literature category got identified as legal candidates to be put online on the internet. Classic literature is defined to be books where the author has been dead for long time - the exact number of years depends upon the country. For India, it is 50 years and for some other countries, it might go up to 75 years.
Summary
1. Newly released books are usually bought fresh from one of these two:
- bookstores
- online book sellers
2. Relatively older books (but the author is alive or has not yet been dead for the last several years) might be bought from one of the following:
- bookstores
- online book sellers
- half-price book stores
- online low-price book exchange sites
3. Classic literature books can be read online for free - no need to buy them - this is your free pool of literature - can be novels, poems, short stories and essays.
To find out which books today are Classic Literature and also to read free, one can try out the following resource along with other resources of similar nature: