Analyzing & Visualizing Data

R is a language and environment for statistical computing and graphics. It is a GNU project which  is similar to the S language and environment which was developed at  Bell Laboratories (formerly AT&T, now Lucent Technologies) by John  Chambers and colleagues. R can be considered as a different  implementation of S. There are some important differences, but much code  written for S runs unaltered under R.

Why  are statistical programming languages important to data scientists?   Please provide a specific use case for a data scientist to apply a  statistical language to a data set.   What are some advantages and disadvantages the R programming language has over the other main statistical programming languages (i.e. Python, SAS, SQL)?