As I'm in the process of buying a Samsung SSD, I just stumbled on this one, which looks a bit different from the regular 2.5" SSD.

 

Don't know though where this would plug in, and can't so right away see any slot on my PC motherboard,  and if it's a better option than the 2.5"

 

That SSD would require either an M.2 slot on your motherboard, or a PCIe riser card (an adapter than lets you run an M.2 SSD via a PCIe motherboard slot -- something like this:  https://www.lazada.co.th/products/kingshare-m2-nvme-ssd-to-pcie-30-x4-adapter-m-key-interface-card-suppor-pci-express-i222265316-s339268798.html)

2 minutes ago, wpcoe said:

That SSD would require either an M.2 slot on your motherboard, or a PCIe riser card (an adapter than lets you run an M.2 SSD via a PCIe motherboard slot -- something like this:  https://www.lazada.co.th/products/kingshare-m2-nvme-ssd-to-pcie-30-x4-adapter-m-key-interface-card-suppor-pci-express-i222265316-s339268798.html)

 

Thanks, so it seems that I need to spend extra money to enable using this SSD, so the 2.5" version is a better option for me.

Agreed, unless your motherboard has an M.2 connector.  On some motherboards it is actually on the bottom of the motherboard (i.e. you need to flip the motherboard over to see/use it), so double-check your motherboard documentation to make sure yours doesn't have an M.2 connector.

Keep in mind that M.2 comes in either SATA or PCIe interface.  The PCIe interface is much faster (3 to 5 times) "if" your M.2 slots supports PCIe.   Most M.2 slots in modern day computers (say only a couple years old) will usually support SATA "and" PCIe M.2 SSD.  But some will not support both protocols...it may support SATA only....or may even be PCIe only.   If it's SATA Only then a M.2 SSD SATA drive like the one in the picture above is no faster than a 2.5" SSD SATA driver   

 

So if your computer has a M.2 slot the first thing you need to do is confirm which interface protocol it supports....that is, PCIe and/or SATA.   Then go shopping for the appropriate M.2 SSD.

Here is a picture of M2 slots on a motherboard to give you an idea how they look like: