confused about bmr, bmi, goal, net calories-too many numbers

I like this definition best for BMR

The basal metabolic rate (BMR) is the base rate at which your body consumes calories for basic metabolic functions like maintaining internal temperature, repairing cells, pumping blood, powering muscles at rest, etc. In other words, it is the rate at which your body consumes calories when at rest.

Body Mass Index, or BMI, is a tool that helps you measure the amount of body fat you have based on your height and weight.

Below 18.5 is considered underweight.
Between 18.5 and 24.9 is considered healthy weight
Between 25-29.9 is considered overweight.
30 and above is considered obese

BMI isn't always an accurate measure to go by because if someone is muscular it can put them in an overweight category when they are in fact a healthy weight.

Your net calories is your caloric intake minus what calories you used.

For example if you ate 1500 calories, burned 300 calories working out, you netted 1200 calories that day.

http://www.myfitnesspal.com/topics/show/186814-some-mfp-basics

http://www.myfitnesspal.com/topics/show/61706-guide-to-calorie-deficits

http://www.myfitnesspal.com/topics/show/226404-bmr-maintenance

http://www.myfitnesspal.com/topics/show/510406-tdee-is-everything

http://www.myfitnesspal.com/topics/show/538381-in-place-of-a-road-map