Magical realism presents a realistic world until one element defies all logic. The magic often sneaks up on an ordinary day, an ordinary life. The sub-genres often tackles with universal truths; it teaches something about the world. Often magical realism is ambiguous and let the reader to her own interpretation. At the closing of the novel, we are never quite sure what was magical and what was not.
Some loose ends are left hanging. The sub-genre questions the assumptions and the values of the society in which it is written.
In Alice Hoffman’s Green Angel, the MC describes how magic helps her family’s garden grow. The author made sure it was not a surprise for the reader, but part of the everyday life of the MC. The magical element appears as real as the real world.
It is not the same as fantasy, because it doesn't offer an alternative world.
For example, in The Sisterhood of the Traveling Pants by Ann Brashares, the story presents a group of teens that couldn't more normal. However, they pass along a pair of jeans that fit all four girls despite their having very different body types.
For example Oscar Wilde's The Picture of Dorian Gray is magic realism. An ordinary man has his portrait done only to realize the portrait shows his soul rather than his physical traits.
Some examples are Graceling by Kristin Kashore or the Gemma Doyle Trilogy by Libba Bray, or the Mediator Series by Meg Cabot, or the Immortals Series by Alyson Noel, or St. Lucy's Home for Girls Raised by Wolves and Swamplandia! by Karen Russell, or the Darkest Powers Series by Kelley Armstrong, or the Poison Study Series by Maria V. Snyder.