handling large data on single computer biological tree and the way it splits into branchestwigsand leaves simple decision rules make it easy to find the child tree in which your data resides look at figure to see how tree structure enables you to get to the relevant information quickly start search age age > <age leaf level danil basu smith asby jones tracy bristo cass figure example of tree data structuredecision rules such as age categories can be used to quickly locate person in family tree in figure you start your search at the top and first choose an age categorybecause apparently that' the factor that cuts away the most alternatives this goes on and on until you get what you're looking for for whoever isn' acquainted with the akinatorwe recommend visiting lamp that tries to guess person in your mind by asking you few questions about him or her try it out and be amazed or see how this magic is tree search trees are also popular in databases databases prefer not to scan the table from the first line until the lastbut to use device called an index to avoid this indices are often based on data structures such as trees and hash tables to find observations faster the use of an index speeds up the process of finding data enormously let' look at these hash tables hash tables hash tables are data structures that calculate key for every value in your data and put the keys in bucket this way you can quickly retrieve the information by looking in the right bucket when you encounter the data dictionaries in python are hash table implementationand they're close relative of key-value stores you'll encounter