It became a national holiday in 1948, but it has been a day of celebration in Japan since ancient times. The fifth day of the fifth month was traditionally called Tango no Sekku and was a festival for boys. Girls have their own festival, called Hina Matsuri (Doll Festival), held on the third day of the third month.
Expressions full disk encryption (FDE) or whole disk encryption signify that everything on disk is encrypted, but the master boot record (MBR), or similar area of a bootable disk, with code that starts the operating system loading sequence, is not encrypted.
Windows only encrypts your drive if you set it up to do so. If you do, the key, which is what is used to make and decode the encrypted data, is your password. If you forget the password, everything on your computer is lost, forever. If you give others the password, everyone can decrypt and view the data. More important than encrypting your drive is data encryption.