There are two basic form factors you should keep in mind when choosing your next SSD! They are 2.5-inch SSDs, like the Crucial MX500 and M.2 SSDs (SATA M.2 and PCI-e (NVMe) M.2), which are much smaller than 2.5-inch SSDs but more expensive.
2.5-inch SSDs are usually mounted inside a computer drive bay although they can be mounted anywhere, even behind a motherboard. To start using the Crucial MX500, you need a motherboard with SATA ports, ideally SATA 2 or SATA 3 ports because SATA 1 offers the slowest transfer speeds (only 1.5Gb/s).
SSDs (Solid-State drives) don't have any moving parts so, they're more forgiving than mechanical HHDs (Hard Disk Drives). SSDs can deliver much faster speeds than HHDs despite the bandwidth bottleneck of the SATA interface, which is 3 gigabits per second (GBps) for SATA 2 ports and 6 gigabits per second for SATA 3 ports.
A SATA 4 interface was supposed to have been in the works but currently, the highest SATA interface available is SATA 3.2 (aka SATA Express), which is capable of 12 Gbps transfer speeds. Most motherboards feature SATA 3 ports though. So, if you use a 10GBps SSD in a SATA 3 port, you are going to be limited to just 6GBps anyways.

With the Crucial MX500, you get a 6GBps SSD, which matches the SATA 3 interface maximum speed. If your desktop computer or laptop was made after 2009, it probably uses the SATA 3 interface. SSDs perform differently, depending on the processor of the computer (AMD or Intel) so, it's crucial to check the SSD specifications to make sure. The Crucial MX500 delivers similar performance whether it's an Intel platform or an AMD platform, which is convenient should you change your setup.
The Crucial MX500 SSD is also backwards compatible with SATA 2 ports and while you won't get 6GBps speeds, it will be much faster than your current HHD and more reliable. Other advantages with SSDs include less heat, quieter operation, and lower power consumption.
If you are someone who moves a lot of folders, containing small and large files, you will find the Crucial MX500 to be a perfect fit because it can provide up to 415 MB/s transfer speeds.
If you plan to run resource intensive applications like Adobe illustrator, Photoshop and massively multiplayer online role-playing games, the Crucial MX500 500GB has fast enough bandwidth for launching these resources. Up to 73MB/s for Adobe, up to 370MB/s for Photoshop and up to 60MB/s role-playing games.
SSDs make the preferred OS drive for many users because of the performance-to-price ratio. For an initial Windows 7 operating system installation, you need around 30GB so, the Crucial MX500 500GB capacity is more than plentiful. If you plan to store dozens of 4K movies (i.e. 50 and above), the Crucial MX500 500GB size won't be enough. Crucial does have a 1TB size available.
Like all SSDs, the Crucial MX500 requires two external connections via a SATA data cable and a SATA power cable. The SSD itself weighs very little (43 grams) and has a thickness of 7mm. A 9.5mm spacer is also included to help fitting the Crucial MX500 SSD in the drive bay of a computer.

As far as performance, it depends on your system. If your system happens to use an AMD A4 5300 CPU, Crucial Ballistix 2666 MHZ 16GB RAM and Windows 7 64-bit OS, you can expect the following performance according to CrystalDiskMark (version 6.0.1)

Sequential Read (Q= 32,T= 1) : 560.3 MB/s
Sequential Write (Q= 32,T= 1) : 520.8 MB/s
Random Read 4KiB (Q= 8,T= 8 ) : 399.8 MB/s
Random Write 4KiB (Q= 8,T= 8 ) : 370.8 MB/s
Random Read 4KiB (Q= 32,T= 1) : 284.3 MB/s
Random Write 4KiB (Q= 32,T= 1) : 259.8 MB/s
Random Read 4KiB (Q= 1,T= 1) : 43.97 MB/s
Random Write 4KiB (Q= 1,T= 1) : 110.7 MB/s