What is it? Edit
"Pandas" stands for "Python Data Analysis Library". It is used for (as the name suggests) analyzing data in Python, and is the preferred and widely used tools in data munging/wrangling .
It is a open-source, free to use (under a BSD license).
What does it do? Edit
It takes in data (like a CSV or TSV file, or a SQL database) and creates a Python object with rows and columns called a data frame, that looks very similar to a table in statistical software (like Excel or SPSS for example).
It is far easier to work with that lists and/or dictionaries through for-loops or list comprehension.