NAS Ultimate Guide: What is NAS, Types & How to Choose

Written by: UGREENSEO



Time to read 8 min

We will take an in-depth look at NAS devices in this article, explaining how it works and categorizing the diffferent types based on their features and configurations. We hope to help readers gain a deeper understanding of NAS and determine which type of NAS is best for their needs. Our analysis will allow you to better understand the advantages and disadvantages of various NAS devices to find the most suitable solutions.

What is NAS?

NAS is an acronym for network-attached storage. It is a device connected to a network with data storage capabilities, and can be used as a standalone file server as it does not need to be connected to a computer. It does not affect the connection of other devices when one device is turned off, allowing NAS to be used in multiple devices that can access the same storage pool.

In short, NAS is connected to a network and data can be stored and shared. It can be thought of as a small, dedicated server primarily used for storing and backing up data. NAS devices are often installed at homes or businesses, making it easy for all users to access and share data. It is more flexible, convenient and easier to manage than traditional storage methods.

what is nas

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Nowadays, users tend to switch operations between multiple terminals, such as cell phones, tablets, laptops, computers, and TV sets. When there is a need for the devices to access the same file, it is not convenient to make a copy of these files on each device. NAS devices are an excellent option for sharing files between devices, especially in collaborative work situations that take up a lot of storage space.

For example, NAS allows devices with limited storage, such as laptops, to edit high-capacity footage online without the need to make additional copies to the computer's internal hard drive.

Some readers may wonder, isn't it easier to enable folder sharing in Windows and allow others to access my storage space? Why do I still need NAS?

In fact, a Windows host with enabled sharing has network access and the functions of a storage device, making it a simple form of NAS. The difference is that a NAS device has a more user-friendly interface and can use some of the more secure array features and file systems. It can install applications such as download tools, web servers, virtual machines, and run independently without a computer.

Moreover, NAS devices have an accessible management page, which allows users to manage their system and use applications on the NAS without a remote desktop. Having a NAS device allows users to leave most of their work on data storage to an independent host, and share functionality across multiple devices.

Users who install a download tool through a NAS device can manage and use the download tool on multiple devices, and the downloaded files will be stored in the NAS device's shared space. The downloaded files can be accessed through various devices that support sharing protocols, such as cell phones, computers and TV sets. Making a copy of the file on each device is not required.

What are the functions of NAS?

File storage and sharing

NAS devices can be used for centralized file storage at homes, allowing files to be backed up on computers, mobile devices, DLNA devices and other devices. These files can also be easily shared with other devices, such as transferring files to other devices through the home network.


NAS devices can be used as a multimedia server to support streaming of multimedia files such as music, photos and videos, making it possible for family members to watch and listen to the same content on any device at home.

Remote Access

NAS devices provide secure remote access, enabling home users to connect their data from anywhere via the internet. This means that files can be accessed on the go, while photos and videos can be shared among family members.

Data Backup

NAS devices offer user-friendly data backup solutions that automatically backs up files and photos on all devices in the home network. This protects home users' data from hardware failures, virus attacks and other issues.

Home Security

NAS devices can also be used as a storage device for home security systems to store images and videos captured through security cameras. This makes it easier for home users to monitor their homes and property.

Create a private cloud

A private cloud can be created on NAS devices at home, allowing users to access their data anywhere and automatically back up critical data on their computers.

Download high-definition movie sources

NAS devices can download high-definition movie sources and send them to a player through LAN.

function of NAS

    What types of NAS are available?

    There are a wide variety of NAS devices at different price points using various types of chips. Many people interested in NAS are unsure which device is suitable for their needs as NAS devices have different functions. We'll break down the types of NAS devices to help you make an informed choice.

    NAS can be divided into three main categories: Private cloud storage, pre-built NAS, and DIY NAS. Depending on the chip used, pre-built NAS and DIY NAS can be further categorized into ARM-based and X86-based models.

    Private Cloud Storage

    Private cloud storage has been rising in popularity in recent years and is a fairly lightweight NAS product. Private cloud storage uses ARM-based processors and does not feature high performance or complex features.

    Some private cloud storage devices have a built-in hard disk drive, while others have a built-in solid-state drive. These lightweight devices are aimed at light users. The private cloud storage app is easy to use and intranet penetration is in the form of account binding, which does not involve IP, domain names and other complex concepts. Most private cloud storage services do not adopt a backend Web architecture, and can only be managed through a mobile app.

    After initializing the device and binding the account, users can access the data in the cloud storage at home through the client of a mobile phone or PC. Users can also share files (data stored in the cloud storage) from the intranet to users on the extranet through the manufacturer's penetration services.

    Doesn't this type of device sound similar to Google Drive and other alternatives? The main difference is that data on private cloud storage is stored on the user's cloud storage device at home, and not on the cloud. Thus, user access to the storage space can be very fast when they are located on the same intranet.

    With a wired connection, private cloud storage can reach transfer speeds close to the limit of a gigabit Ethernet connection. (Note: Gigabit [1Gbps] wired network limit bandwidth is 113MByte/s). There is no significant performance gap compared to most pre-built NAS devices. In other words, private cloud storage is a great choice if you just need a high-speed shared storage space for your intranet and you don't need additional NAS features.

    Users are advised to have a clear understanding of the product functions and consider whether private cloud storage can meet your needs before purchasing.

    Most private cloud storage devices are single hard disk drives, while some private cloud storage devices have more than two hard disk drives that can build arrays to improve data security. Single hard disk drives do not feature data redundancy, where all data is lost once the hard disk drive is broken. Users of single hard disk drives are recommended to enable background file synchronization for off-site backups.

    Pre-built NAS

    Mainstream pre-built NAS apps include Synology, QNAP, Asustor. Other emerging brands, such as Ugreen, have their own set of NAS systems used in their ARM- and X86-based devices.


    Unlike private cloud storage devices, pre-built NAS devices tend to have access to more functional arrays and file systems, as well as more comprehensive document rights management. This type of NAS also has an app center offering specialized features.

    What is RAID?

    RAID refers to the use of multiple hard disk drives to store the same data for backup in different places. To ensure data security, the array can continue to run when there is hard disk drive failure.


    As previously mentioned, NAS is a computer that makes its own storage accessible to other devices through a network. Thus, a computer can also be turned into a NAS device by installing a NAS operating system.

    The biggest advantage of DIY NAS is the ability to choose the right operating system and hardware configuration based on your needs. The cost of hardware is also lower than pre-built NAS devices.

    Mainstream NAS operating systems include TrueNAS, unRAID and OMV 3, which focus on different file systems. However, these systems feature usability optimization with the core function of file storage and sharing. Users should first determine whether these operating systems meet their needs if they want to build a DIY NAS server.

    Users can also choose an operating system that they are familiar with, such as Windows, and configure it with specific NAS functions.

    What type of NAS should I choose?

    Who should use private cloud storage?

    Only a small number of tools can be selected in the app center of private cloud storage systems. For example, most private clouds cannot install download tools for PT and AV database servers such as Plex, nor can they realize co-location. Private cloud storage is suitable for people who only have storage needs and do not require other functions.

    Who should use ARM-based NAS?

    The disadvantages of private cloud storage listed above are not found in ARM-based NAS. ARM-based NAS can install most server software as its app center has many features. ARM-based NAS has 2 to 5 hard disk drives to choose from, allowing the building of a high-end storage array to ensure data security.

    Both private cloud storage and ARM-based NAS are perfect for newbies. Private cloud storage has a lower learning cost, and is especially suitable for beginners who use mobile phones and laptops, and can easily free up storage space on these devices. In contrast, ARM-based NAS is more functional and suitable for users who need advanced applications.

    Who should use X86-based NAS?

    X86-based NAS has a stronger processor performance than ARM-based NAS, with faster opening speed and response time of various apps, as well as more stable transmission speed. In addition, an app does not have a major effect on the system speed. Some X86-based NAS devices are configured with 2.5G or 10Gbps Ethernet ports, which can realize high transmission speeds. SSD cache can also be added to enhance the array's performance. X86-based NAS devices can also be run on software such as Docker and virtual machines.

    Who should use DIY NAS?

    DIY NAS is suitable for people who care about cost-effectiveness, have hands-on skills and high requirements for data security and privacy breach. With the right type of accessories, you can realize stability and performance at lower prices.

    The Linux-based operating systems of DIY NAS are not well known to most novice users, but getting started on DIY NAS is not that complicated if you follow the tutorials. Even beginners who are patient and equipped with basic computer knowledge can try to build their own NAS system on their computers to experience the benefits of NAS.


    NAS is a convenient network storage device that provides secure file storage and sharing, supports multiple device access and data backup. Users need to select different types of NAS devices based on their specific needs and take into account the performance, features and security of NAS devices. We hope this article can help you better understand NAS to make an informed choice.