Well MD5 hash is 128 bit fingerprint, MD5 is one of the strongest and irreversible hash , mean once hash is generated for some data it cant be reversed. The MD5 hashing algorithm always produce 128 bit hash value and it have 512 bit block size. Its useful for securing passwords and other sensitive data like credit card numbers etc in databases. So that attacker never get hand on actual data , let say if user have password mypassword123 on website and the website use md5 hashing to store password in their database and so if site is hacked and database is compromised then attacker will only get md5 hashes from database not actual user passwords and so with these md5 hashes he cant event login to user accounts because website will be first converting raw password to md5 hash and then will be comparing with hash saved in database and then user will be login. Also MD5 hash is useful for checksum purposes to verify data integrity , let say if you have 5 pages of data you can calculate its md5 hash and later you can recalculate its md5 hash if its not same to previous hash then it mean data is tampered by someone.
Well Useotools Online MD5 Hash Generator is one click tool that can calculate md5 hash for your data weather its your raw password or other sensitive data. Usage of this tool is way simple just pate your data in text area and press blue button to calculate hash of it.