A decimal number can be defined as a number whose whole number part and the fractional part is separated by a decimal point.

The dot in a decimal number is called a decimal point.

Explanation: For example, \$108.9\$.
Here, \$108\$ and \$9\$ are separated by a point. So, \$108.9\$ is a decimal number.

Decimals that have the same number of digits to the right of the decimal point are referred to as like decimals..

Explanation: For example, \$110.7\$ and \$115.8\$, in \$110.7\$ and \$115.8\$, there is only one decimal place after the decimal point, so \$110.7\$ and \$115.8\$ are like decimals.