Organisms can be divided into smaller and larger groups based on their similarities and dissimilarities. This scientific method of categorizing plants is called classification. Thus a classification has various levels which constitute taxa. Each taxon (singular) indicates a specific level of similarities and dissimilarities.
Family is one such taxon in this hierarchy of taxons. Thus, in short a family is a group of genera that are closely related depending on the degree of their similarities. Also, every family has some specific characteristics.
There are many classification systems given till date. But the most widely and conveniently used one is the classification system given by George Bentham and Joseph Dalton Hooker. The same classification system is followed here but the new names for the families or some segregations from one family are taken into consideration for the ease of search.
Below is the list of families arranged alphabetically. The names of families in the brackets refer to their earlier family names.