What is an FTP Server?

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By Gulshan Negi

FTP server stands for File Transfer Protocol Server. Basically, FTP servers are software applications that allow the transfer of files from one source to another. It offers the easiest solution to businesses who want to keep their data safe and secure. If you are looking to back up your company data to prevent data loss, a hosted FTP server might offer you the right solution. But to decide if you need an FTP server for your business or not, you have to know more about the same. Here we have prepared a complete guide on ‘what is FTP server?’ and ‘how does it work?’ Scroll through to know more.

What is File Transfer Protocol (FTP)

Before you dive into the FTP server and become familiar with its mechanism, you first need to develop a good understanding of FTP.

Basically, FTP is a protocol for transferring files between two computers in a secure way. When you transfer a file over the internet, there is a possibility of it being hacked or intruded on in any way. FTP provides you the safest way possible to complete this transfer over a secure network. The transfer is made via a Transmission Control Protocol or Internet protocol.

What is FTP Server?

FTP servers provide the solution to complete the process of file transfer by placing a secure server between the two computers. When you use an FTP server, you either upload a file or download a file. The computers do not interact directly, but the server deals with both of them to facilitate file uploading and downloading.

When you upload a file, the file gets transferred to the server on which the receiving end sends a command to download it through a TCP/IP protocol. An FTP server acts as a security layer between the two computers that want to exchange files with one another.

FTP server works on a client-server architecture where the nodes are clients and the FTP server acts as the server. In an anonymous connection, the user can use the server without using any credentials but things are different when the services need permissions to access them.

What Does File Transfer In an FTP Involve?

Login – The client computer needs to have an FTP client software installed on it, which allows you to access the FTP services by using credentials, i.e., a username and password. As you log in, the server sends you a message identifying the login. This practice is helpful to take necessary actions in case any unknown login is detected. But not all the servers demand credentials; Some free, open-source servers allow you to access them without requiring a login.

Connection – Connection can be of two types: active and passive. When a client is accessing the server from within a firewall, it is an active connection mode where the user asks for permission from the server to make necessary changes on the server. The server grants access and files are transferred.

In the passive mode, the server only acts as a listener and does not communicate back with the client.

Data Types – FTP uses four data types for file transfer, i.e. ASCII, EBCDIC, Proprietary, and Binary.

  • ASCII is the standard data type to make the transfer of plain text, numbers, and special characters.
  • EBCDIC code is used when both hosts use EBCDIC as their internal character set.
  • Image, drawing, application code, etc., are transferred via Binary data type, which transfers data in binary format, i.e. 0 and 1.
  • The proprietary data type is used to transfer data in a format that is compatible with both receiver and sender.

Modes of Transfer – The data transfer can be completed in three modes – stream, block, and compressed.

In-Stream mode, data is transferred in a stream. TCP manages the entire transfer process.

In Block mode, data is broken down into blocks and these blocks are sent to TCP with a header, byte count, and data. TCP only undertakes the transmission.

In Compression mode, the data is compressed before transmission.

Security – The main purpose of using the FTP is to transfer a large number of files securely via an external server. However, if the server does not guarantee secure file transfer, the purpose of using it fails. Thus an FTP server must use SFTP and SSH to ensure the safe transfer of files to save them from brute force attacks, packet capture, spoofing, etc.

How Does an FTP Server Work?

The basic function of an FTP server is to send and receive files. A client either puts a file or gets a file from the server. Two ports that are majorly used in this FTP transfer via TCP/IP are port 20 and port 21. While port 20 is a data port, port 21 acts as a command port.

A client who needs to send a file puts it on the server by sending a request. A client who needs to receive the file sends another request to the server asking for it. The FTP server listens to both of them and responds to them accordingly.

For an organization where employees are located in remote locations, FTP can be used to transfer non-confidential files. It is a cost-efficient way to exchange a large number of files with your business partners, employees, and customers.

Use of FTP Servers in Different Environments

There are different uses of FTP servers within and external to the organization. Here are some examples:

  • Employees can transfer documents with remotely-located colleagues.
  • Developers can use it to transfer application codes to the production team as file sizes are relatively large.
  • Organizations can back up data on disaster recovery sites to access it in case of emergency.
  • It can be of great use to collaborate with suppliers, dealers, business partners as well as customers.
  • Employees can share their views with the outsource staff.
  • There are several other industries and businesses which can benefit from the FTP server services like legal services, banking, finance, IT sector, etc.

Why Should You Use FTP Server?

You must have developed a good idea about the advantages of using FTP servers. However, if you need more reasons to use an FTP server, here are ones that you need to check out:


In the internet world, security is a major concern, and FTP servers ensure complete security when it comes to transferring files. Most FTP servers today add a layer of security by encrypting the files. Secure or SSH File Transfer Protocol allows you to transfer files without worrying about them being hacked.

Large File Size

When you transfer large files through a common medium such as by emailing or through some instant messaging platforms, you may receive error messages saying that it is too large to be transferred. But that is not a problem with FTP servers as they are designed to help you transfer large files. You can even send files having a size in Gigabytes.

Disaster Recovery

Losing your valuable business data is never an option but when you keep your important files in your hard drive it becomes much more vulnerable and prone to data loss. Thus, having cloud backup is essential. You never want to lose your data, and FTP servers help you to regularly backup even your most sensitive data in a secure way and also restore the data conveniently.


In FTP, you can restrict access to the files you have uploaded on the servers. While sharing files on an FTP server all the users on the same network do not require to have the same level of authority or access to the file. Hence, while sharing files through an FTP server you can designate authority for the files to the specific users you want. Hence, you gain more control over your files.

Automatic File Transfer

When it comes to backing up large files it’s a hectic job as It takes a good amount of time to upload large files on the server. But with FTP servers you can manage things in a way easier manner. While transferring files to an FTP server all you need to do is to schedule the file transfer time as per your convenience and things will process automatically on your scheduled time. You can get the service either from a managed FTP solution provider or you can do it on your own using simple FTP send and receive command lines and with the help of the Windows Task Scheduler.


Now you know everything you need to know about FTP servers, right from the usage to the benefits. Hopefully, all the information that we have put through will help you make an informed decision about your data and its transfer. You can use an FTP server to secure your data from being lost or hacked during a transfer.

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