What is Dropbox? How Does it Work? Find Your Answers Here

What is Dropbox and How Does it Work?
The latest storage destination for all your files is Dropbox. Not only does this feature allow you to store your data, it also allows you to share the same with others. Still wondering how is this sharing possible? Here is the answer.
Techspirited Staff
Last Updated: Sep 6, 2018
Retrieve Deleted Files?
Dropbox will keep deleted files for 30 days before permanently deleting it. So, you will always have a month's time to restore those important, yet deleted files.
Dropbox is a one-stop destination for all your file needs. Though the Internet has been around for a while now, it was only after the advent of Cloud Storage that we could truly use the Internet to store data virtually.
Drew Houston and Arash Ferdowsi are the brains behind the concept of Dropbox. The company is based in San Francisco and is funded by Sequoia Capital, Accel Partners, and Amidzad.
You can create an account on their website for free to get limited storage space (2 GB), or opt for a paid subscription if you wish to get more storage space (up to 100 GB). Let us get acquainted with this amazing way of storage and see how it works.
What is Dropbox?
Dropbox is an online storage facility that uses Cloud Storage to create backup facilities for all your files. You can share photos, docs, videos, and files using your Dropbox account. These files will be available on the computers, iPhones, iPads, and Android devices that have the Dropbox application, and are available on the Dropbox website as well.
The concept of Dropbox is such that you can share files with others. The next time you create an important document, make sure you share it using Dropbox, so that you have a backup copy of the same. 256-bit AES encryption is used to secure the stored files. You can make changes to these files even after they are stored in Dropbox.
Technology Behind Dropbox
The software program (server and client) of Dropbox is written in Python. Python is a high-level programming language that allows users to write codes in a few lines as compared to other programming languages.
On Windows, the py2exe utility is used for the source and application coding. On Linux, the bbfreeze utility is used for static linking the Python interpreter and the OpenSSL library.
Storing a File
When you store any file on Dropbox, here's what happens at the backend:
  • You will drag-drop the file that you wish to store to the designated folder in your account, or copy-paste to the respective folder.
  • Once the file is saved, it is synced to their online servers.
  • These files are then encrypted and stored in Amazon's Simple Storage Service (S3) in different data centers across the United States. Amazon's S3 is a web service interface that provides storage for Internet users.
The network connection is peer-to-peer, but in case you want to share files with your friend, it is not mandatory that both of you be online. The Dropbox server will store the files with the relevant changes. These edited files will be automatically updated into individual folders.
Server Side Process
When you wish to upload a file which is 4 MB, here is what happens at the server side.
  • Dropbox will check the size of the file. If it is <4 MB, it will continue with the process, but if it is >4 MB, the file needs to be broken into smaller units of 4MB. The reason being—Dropbox stores files in blocks of 4 MB.
  • If the file fits into one block, the client side hashes the file. The hash function is an algorithm that will map data of variable length into a fixed length, which means the variable length file will be converted into a 256-byte string (in this case) and sent to the server.
  • Once on the server, the cache will check if a file with the same hash function already exists. If the file exists, the cache will simply return its copy, but if the hash function doesn't exist, the file will be uploaded to a new location.
LAN Sync
In case of files accessed and shared on a local area network (LAN), the LAN sync technology is used. Here is how the sharing is performed:
  • You have created a file and it is saved on your computer's Dropbox.
  • When you make any change to the file, the syncing process is initiated.
  • All the computers and shared folders that are linked to your computer will download this version of the file.
  • However, with the LAN sync function enabled, the Dropbox will first check the LAN for any new file instead of checking for it on the central servers. Thus, the processing time reduces.
Getting Started
If you are new to the world of Dropbox, here's the process to get started with this 'feature' (as quoted by Steve Jobs).

1. To start using Dropbox, you will first need to download it on each device that you need to keep in sync with your account.
2. During the installation process, you will be prompted to enter a username and password. You have to create just one account, irrespective of the number of devices you want to keep in sync.

3. Once the installation process is completed, a Dropbox folder will be created on your hard drive.
4. You can drag-drop files in this folder, and they will automatically sync with other devices.

5. These files are now available on the website as well as on the shared devices' Dropbox folders.
The next time you think of buying a USB stick or hard drive to store your files, try Dropbox. You will be surprised to see how easy it is to share and access your files from mobile devices.