How is realism portrayed in Daniel Defoe's Moll Flanders?

In his novel Moll Flanders, Daniel Defoe portrays realism through a first person narrative. In a voice that must have been shocking for that time (the novel was written in 1722), Moll Flanders tells the reader in blunt, unromanticized language about her sexual exploits:

Then he walked about the room, and taking me by the hand, I walked with him; and by and by, taking his advantage, he threw me down upon the bed, and kissed me there most violently; but, to give him his due, offered no manner of rudeness to me, only kissed a great while.

It also discusses the difficulties of being an unmarried woman:

Thus the Government of our Virtue was broken and I exchang'd the Place of Friend for that unmusical harsh-sounding Title of Whore.

It is through her narrative that the reader really gets an impression of what life in eighteenth century England and the American colonies was like, both from the side of the rich and the poor.
In the story, Moll tells the reader how she was born a in prison in England before being transported to America, where she became relatively well educated. After a series of misfortunes, Moll becomes a thief on the streets of London and ended up in prison. The story ends with Moll meeting an old flame and moving back with him to the American colonies.

Moll Flanders is realistic in that it's unsparing in its depiction of the sordid underbelly of eighteenth-century London life. The heroine of the story—if that indeed is the right word—is a prostitute and a thief who lives among the dregs of the city. Defoe doesn't attempt to sugar coat the lives of those such as Moll who occupy the very lowest rungs of the social ladder. We're left in no doubt that life for the London poor is nasty, brutish, and short.
Defoe adds to the realism of his story by the method he uses to tell it. Moll Flanders is largely episodic in structure, moving rapidly from one event to the next. As well as making the story a good deal more colorful, this narrative approach also makes it more life-like, more credible. There's certainly nothing contrived about Moll Flanders; it reads like a genuine autobiography about a real-life individual. This is due to Defoe's rejection of traditional plots in favor of a more picaresque method of story-telling which emphasizes the sheer ordinariness of Moll and countless others like her.