LaCie has external disk drives that use both USB 2.0 and 3.0 connections that range in size from 120 GB to 4 TB of data storage. They sell both desktop as well as mobile hard drives, with some of the mobile drives being solid state disks (SSD) which allows for reliable data storage.
The MacBook Pros come with an excellent built-in DVD/CD rw drive. Most name brand external drive can usually be added if required. The LaCie drives are popular and often include their LightScribe software enabling label printing directly onto the disc.
"Thumb Drives come in a variety of sizes. The most common sizes hold thousands of songs and are 4-12 GB. The largest available on the market at this time is 256GB. As technology has grown, so have the sizes of thumb drives a.k.a. flash drives."
There is nothing built-in. HP owns the LightScribe technology and Apple has not chosen to license it from them or to install LightScribe compatible drives in the MacBook Pro. That's not to say that you couldn't purchase a mac compatible external DVD burner that has LightScribe technology. The software to control it is freely available from LightScribe.
Flash drives have a whole range of sizes. But the most common sizes are 1 GB, 2 GB, 3 GB, and the most common and cheapest is the 4 GB size. Some even offer larger sizes, such as 8GB and there are even some that are 16 GB. These larger sizes cost more, though.
250gb external hard drives come in brands such as Apricorn, Axiom, and G-Drive. More well known brands include Toshiba and Seagate. The most famous brand is Sentry Safe.
It is not a phyiscal input (or human interface) but it is a data input device. which means it will come under external drives.
Hard drives come in many standard sizes, ranging from a few megabytes to over a terrabyte.
External DVD drives are obtainable for laptops. Many of them are slimline portable models especially suitable for traveling. They are useful for backing up data or watching DVD movies on ultra-slim laptops which do not come with an internal DVD drive.
WD makes HDDs in many different sizes. These days, TB is the desired sizing, so you can find them in one, two or even five. I'm sure they have much smaller sizes at a reduced price. Why not check their site?
Most external hard drives come with the necessary USB cable. Most electronics retailers carry USB cables if you need to buy an extra.
WD Hard drives come in most sizes. You can get old ones cheaply for around 250GB, or you can get 2TB ones for more money. In my opinion, the best value for money would be a 1TB one, as here in the UK you can get one for around �80.
A optical drive is used to read CDs and DVDs for data, listening to music, or watching movies. They do not come in different sizes like a hardrive or flashdrive but you need to get the right model for the computer that you have. Check with the manufactor of your computer to determine which model of optical drive you will need for your computer.