The most common type of logarithm table is used is log base. Before calculators the best way to do arithmetic with large or small numbers was using log tables. The logarithm is denoted in bold face.
Therefore 3 is the logarithm of 8 to base 2 or 3 log 2 8.
A key tool that enabled the practical use of logarithms was the table of logarithms. Subsequently tables with increasing scope were written. For instance the first entry in the third column means that the common log of 200 is 03010300. First lets find some log values and see what they mean when re-expressed in index notation.