A sex shop is a shop that sells products such as sex toys, pornography, erotic lingerie, erotic books, and safer sex products such as condoms and dental dams. The terms "Adult Video Store" and "Adult Book Store" are commonly used to refer to sex shops that sell or rent pornographic videos, books, and magazines.
In most jurisdictions, sex shops are regulated by law, with access not permitted to minors, in most countries/states, the age depending on local law. In case of doubt, on entering a sex shop, one may have to present a valid ID. Some states/countries don't tolerate sex shops at all, e.g. many Islamic states.
Near borders of countries with different laws regarding sex shops, shops on the more liberal side tend to be popular with customers from the other side.
F Street Adult Gifts and Books is a reminder of the time when prostitutes and homeless people were more common on Main Street than the restaurant patrons and families El Cajon's downtown is beginning to attract.
The bookstore, which is open 24 hours, has operated here since 1985, so it is exempt from laws passed since then that effectively shut out adult-oriented businesses.
Ironically, the bookstore on Main Street stands next to the corporation, which is working to turn around the area.