Does a factor mean the same as a highest common multiple?

Answer 1

No.

When talking about factors and multiples the numbers are integers (whole numbers).

A factor of a number means that the number is a multiple of the factor; the factor divides into the number without any remainder.

There is no such thing as a Highest Common Multiple - it is always possible to find a higher common multiple (by adding the Lowest Common Multiple to the supposed highest common multiple).

There is a Lowest Common Multiple (LCM) which is the smallest number which is a multiple of two or more numbers. It is also called the Least Common Multiple, or when working with fractions it can be referred to as the Least Common Denominator as the two or more numbers are the denominators of the fractions and equivalent fractions are being sought to be able to do an addition or subtraction.

There is a Highest Common Factor (HCF) which is the largest number which divides into each of the two or more numbers without remainder. It is also called the Greatest Common Factor. If the numbers are relatively prime (or co-prime) their HCF is 1.

Answer 2

No, it does not.