For a basic barbecue sauce, all you have to do is whisk together ketchup, light brown sugar, white wine vinegar, Worcestershire sauce, and paprika.  Google bbq and you will find more than you ever wanted to know!  Some say there are five kinds, some say four kinds of sauce.   Some believe barbecue is only sauces, other include dry rubs.  Below are some suggested “variations on a theme” to change the basic sauce.  There is even one that substituted wine for the vinegar.  

Ingredients: 

• 3/4 c ketchup
• 2 Tab light-brown sugar
• 1 Tab white-wine vinegar
• 1 Tab Worcestershire sauce
• 2 tsp paprika
• 1/4 to 1/2 tap cayenne
• pepper, (optional)

Directions:

Whisk together.

Source:  marthastewart.com

There are five types of BBQ sauce, and their base ingredients define them.

Tomato Based BBQ Sauce – They are often sweet and compliment meats cooked in a sugary rub. Ex: Kansas City BBQ Sauce, St. Louis BBQ Sauce, Texas Style BBQ Sauce, Memphis style BBQ sauce.  Add-ins: crushed tomatoes, lots of brown sugar (The average serving contains 14 grams of sugar.), molasses, smoked paprika, black pepper, chili powder, garlic powder, onion powder, red pepper flakes, hot sauce, yellow/ground mustard.
Vinegar Based BBQ Sauce – Vinegar based sauces are astringent and strong. Ex: North Carolina Style BBQ Sauce (no tomato), Piedmont/Lexington BBQ Sauce (contains some ketchup but is still vinegar based).
Mustard Based BBQ Sauce – Mustard based barbecue sauce is tangy and peppery  (little sugar, no tomato). Ex: Carolina Gold aka South Carolina style BBQ sauce.
Mayonnaise Based BBQ Sauce – This sauce is creamy with a horseradish kick which compliments smoked poultry (no tomato – maybe). Ex: Alabama white sauce.
Worcestershire Based BBQ Sauce – Served with Kentucky style mutton, Worcestershire BBQ sauce is astringent, sweet, and bold. Ex: Kentucky BBQ sauce.