Operating Systems | CompTIA A+ 220-1002 | 1.1

In this video you will learn about common operating system types & their purposes as it relates to: 32-bit vs. 64-bit, workstation operating systems, cell phone/tablet operating systems, vendor-specific limitations, and compatibility concerns between operating systems.

32-Bit vs. 64-Bit File Systems

An operating system is system software that manages computer hardware, software resources, and provides common services for computer programs. One of the main functions of an operating system is to enable the computer to keep track of all of the files used on the device. In computing, a file system controls how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stops and the next begins. By separating the data into pieces and giving each piece a name, the data is easily isolated and identified. When utilizing Windows operating systems, depending upon the type of file system a user utilizes for a hard drive can affect the following:

  • Rules pertaining to how large a logical drive (drive letter) can be & whether or not the hard drive can be used as simply one drive or if the drive is divided into several smaller drives or whether the hard drive must be multiple separate drives altogether.
  • Data storage efficiency (maximizing the use of available space).
  • Implementing measures to protect a system from tampering.
  • The ability for a drive to be accessed by more than one operating system.

Windows OS can support three types of file systems for hard drives & USB flash drives: FAT32, NTFS, & exFAT.


FAT32 (file allocation table 32) is the 32-bit version of the FAT file system. FAT32 format was employed on Windows PCs (in 1995) prior to the NTFS file system. FAT32 is widely used for USB drives, flash memory cards and external hard drives for compatibility between all platforms. FAT32 has some of the following characteristics:

  • Has a 32-bit file allocation table that allows for 268,435,456 (2^32) entries per drive. Entries are allocation units or folders that can be used by a file.
  • FAT32 allows for the root directory to be located anywhere on the drive with an unlimited number of entries.
  • For drives as large as 16GB, FAT32 uses an 8KB allocation unit size.
  • FAT32 allows for a maximum logical partition size of 2TB.
  • Compatible with Linux & macOS
  • For partitions larger than 32GB, Windows can’t create a FAT32 partition.
    • Although Windows can use a larger partition if it already exists.
  • Mainly used to format flash memory cards & USB flash drives for use in
    • Workstations
    • Media players
    • Smart TVs
    • Printers
    • Cameras
    • Other USB enabled devices.

Some of the limitations of FAT32 include:

  • It can only support individual files up to 4GB in size
  • Can’t use file permissions
  • Doesn’t support journaling which enable corrupted files to be fixed

exFAT (FAT64)

exFAT (extensible file allocation table, aka FAT64) is a file system that supports 64-bit addressing introduced by Microsoft in 2006 that is optimized for flash memory such as USB flash drives and SD cards. exFAT functions just as easily as FAT32, although it has many more improvements in terms of capacity and scalability. The main features of exFAT are:

  • Can support volumes larger than 32GB.
    • The recommended volume size is 512TB.
    • The theoretical size is 64ZB (1ZB = 1 billion terabytes).
  • Supports maximum file size increases of 512TB & 64ZB.
  • exFAT file system structure allow for improved performance with flash media and movie recording.
  • Supports Universal Time Coordinate (UTC) date stamps.
  • Can be used in Windows 7, 8/8.1, & 10.
File System Formatting Options

Workstation Operating Systems

Operating systems can be classified as either: open source or closed source. Open source software is a source code that is made freely available for possible modification and redistribution. Closed source software (proprietary software or vendor specific) is computer software for which the software’s publisher or another person retains intellectual property rights, usually copyright or patent rights of the source code. To access closed source software, a user has to be granted permission and typically pay a licensing fee.


Microsoft Windows (simply known as Windows) is a group of proprietary graphical operating system families, all of which are developed and marketed by Microsoft. Windows is the most popular & utilized closed source software product in the world. In the 1980s, Microsoft started off by providing the operating system for IBM personal computers using a command line input system called DOS (disk operating system). Beginning in the early 1990s, DOS was replaced with a GUI (graphical user interface) system called Windows. In 1995, Microsoft introduced Windows 95 which eventually lead way to future versions of Windows such as: XP, Vista, Windows 7, 8/8.1, and 10.

Apple Macintosh OS

Apple’s closed source software is called macOS and was released in 2001. At the time of this writing, the latest version of macOS is Catalina (version 10.15.7). macOS software was specifically designed to integrate with Apple’s mobile devices that use the iOS operating system, such as the iPhone, iPad, Apple Watch, & Apple TV.

macOS Catalina


Linux is a family of open-source (source code is free) UNIX-like operating systems based on the Linux kernel, an operating kernel first released in 1991 and named after Linus Torvalds. Linux is typically packaged in what is called a Linux distribution (distro). Some of the distros are available as command line interfaces and others as GUI distros. The most popular distros of Linux are Ubuntu, Mint, Kali, & Red Hat. There are companies such as Red Hat that modify the Linux source code and then charge individuals/organizations for support for the modifications.

Linux Ubuntu Distro

Cell Phone/Tablet Operating Systems

The two major mobile operating systems for smartphones are Android and iOS. There are very few people who own a smartphone that utilizes Windows Mobile. Two of the main differences between an Android and iOS smartphone are:

  • Android OS updates are provided by the wireless carrier.
  • iOS updates are provided by Apple, but wireless carriers provide network-specific updates for the actual iPhone.

Microsoft Windows

Windows Mobile is a discontinued family of mobile operating systems developed by Microsoft for smartphones and personal digital assistants. In 2019, Microsoft ended its support for the mobile OS and essentially exited the smartphone market altogether. Microsoft’s Surface Pro tablet runs off of Windows 10 and pretty much functions identical to a laptop.


Android is a mobile operating system based on a modified version of the Linux kernel and other open source software, designed primarily for touchscreen mobile devices such as smartphones and tablets. Android is developed by a consortium of developers known as the Open Handset Alliance and is commercially sponsored by Google. Android is a free and open source software where its source code is known as Android Open Source Project (ASOP), whose mission is to maintain and develop the Android platform. One of the main draws to Android is that the code is open source which allows for developers to modify it & freely create applications for it.

Android Home Screen

To figure out the current version of your Android device:

  • Go to Menu > Settings > About Phone (or About) > Software Information
Android Software Information

Be mindful that due to various licensing agreements that allow for customization, Android devices are likely to have different interfaces & features from different vendors.


iOS is a closed source software mobile operating system created and developed by Apple exclusively for its hardware. It is the operating system that powers many of the company’s mobile devices, including the iPhone, iPod Touch, and iPad. Apple iOS is based on macOS which has its roots in UNIX.

iOS Home Screen

To figure out the current version of your iOS device:

  • Go to Settings > General > About
iOS About Screen

Chrome OS

Chrome OS is a Linux-based operating system designed by Google which is installed on Chromebooks (inexpensive laptops designed to run web-based apps). It is derived from the free software Chromium OS and uses the Google Chrome web browser as its principal user interface. However, Chrome OS is proprietary software.

Vendor-Specific Limitations & Compatibility Concerns

Virtually all smartphones in the US utilize either Android or iOS. Each OS has many benefits that keep a loyal base of users on both sides. Apple iOS is a vendor-specific product and some its benefits are:

  • Apple controls the OS
    • Offers better quality control and safety of Apple products
  • Apple iOS products integrate with other Apple iOS products much more easily due to a closed source platform

Potential downside to iOS platform:

  • iOS doesn’t play well with non-iOS devices

Android OS is an open-source platform and some of its benefits are:

  • It has way more apps available for the platform
  • Android devices are often way cheaper than iPhones & iPads

Potential downside to Android platform:

  • Android allows the use of third-party apps which can present security issues for users and their devices.