As you can see from the table below, Bayern (Bavaria) is the largest Land in terms of area, whilst Nordrhein-Westfalen (North Rhine-Westphalia) has the largest population. If you click on the names of each federal state, you will be taken to the homepage of the Land. Many of these homepages also have English versions.
The English translation of the German Länder names
Many of these German Länder have English equivalents - although the English version of Mecklenburg-Vorpommern is no less of a mouthful! Note in particular the very different German name for what we call Bavaria.