Scientific notation is a way of writing very large or small numbers as the product of a number between 1 and 10 with a power of 10. Positive exponents mean moving the decimal point to the right, while negative exponents mean moving it to the left. The exponent tells how many places to move the decimal by. Converting between standard and scientific notation involves moving the decimal point and determining if the exponent should be positive or negative based on if the number is greater or less than 1.