Approximately 3.5 inches.
Internal Desktop refers to electronic computer parts that are designed to be installed inside a desktop computer. e.g Internal Desktop Hard Drives are hard drives designed to be installed inside a desktop computer.
Laptop hard drives are very similar to desktop hard drives, indeed they work in exactly the same way and even use the same interfaces. However laptop hard drives are designed to be much smaller (2 inches as opposed to 3.5) and draw less power than desktop hard drives. As a result laptop hard drives are usually much slower in terms of data transfer and have much smaller storage capacity than a desktop hard drive of the same year manufacture. With an adapter it is possible to use a laptop hard drive in a desktop computer, and if mounted externally it is also possible to use a desktop hard drive on a laptop.
Yes it is....
The physical size of a hard drive varies by the type of the computer it is placed in. Desktop hard drives are approximately 3.5" wide, and 1" high. Laptop drives are approximately 2.5" wide and 1/3" high. Capacity varies widely. In these modern size formats, you can typically find drives anywhere from 20 GB to 1.5 TB.
Typically, hard drives are mounted in the front of a desktop PC and somewhere on the underside of a laptop. External hard drives will be wherever you place them.
Ram,Hard Drives,Disc Drives
The number of hard drives that can go in a desktop is more limited by the space you have within your computer's case and the number of ports on your motherboard rather than operating system limitations. I have heard that you can have up to 24 drives in Windows including internal and external drives. Right now, I have 5 drives attached to my desktop. To determine how many drives you can have in your desktop you should count up the number of SATA or IDE ports on your motherboard and count up the spaces in your computer case. Also, consider using external hard drives to increase your storage capacity.
Yes. SSDs (Solid State Drives) are still much more expensive per gigabyte than magnetic hard drives, so they are still uncommon in desktops and mainstream laptops.
In other words, is it correct to say that if you are talking about an external hard drive with a USB connector. you can use it for either a desktop or laptop? Yes but no at the same time... Both of the Hard drives work exactly the same but the destop Drive(3.5") is larger than the Laptop hard drive.(Ranges between 1" and 2.5")
If you are talking about the slots in the computer that you plug an external hard drive into, they are called USB ports.
Ata/pi-6
There are several major hard drive companies that produce hard drives to back up answers. These include Fujitsu, who mainly produce hard drives for the server market, and Seagate, who produce a wide range of high end hard drives.