We need the knowledge of logarithms in many places including calculating time complexity of an algorithm to advanced data analytics calculations. Here are some useful references to learn about logarithms online.
Introduction to Logarithm (DeltaStep) - Explanation is good, but pronunciation seems not perfect at times.
If you are a software developer who work with data structures and algorithms you might have heard about Asymptotic Analysis. Most of us would stick with the basic knowledge of Big O notation such as O(n), O(n2), O(log n) etc. However, understanding more about these can make you a good engineer from just being a programmer.