SSD = solid state drive
HDD = hard disk drive
HDD uses a spinning disc and a moving head to read and write to the disc, these are less expensive and can hold more data
Because they rely on moving parts they have extra failure modes that SSD won't have, but either can fail
In a laptop an SSD would be best because it is often moved around and jolted, lol, and laptops are generally not used to store alot of data
SSD are "chips" like RAM, but can store/hold data without power, these can't store alot of data, but can access the data faster than HDD
A "USB Stick" is an SSD
An HDD can store 4 times the data as an SSD for same cost
In a home PC using an SSD as the primary drive for operating system can be a good choice, and then HHDs as slaves to store data
Laptops can usually only have 1 drive, no room, but SSD is still a better choice
These days you can rent data space from many companies, called "cloud storage", these companies have at least 2 locations that backup your saved data so if its "important" it shouldn't ever be "lost" from any drive failures, damage drives or "stolen" devices
And the "cloud data" is accessible from any internet device anywhere if you have the account info to access it
If you are paranoid about your data being out of your direct control there are encryptions you can use when storing data on "cloud servers", but you do need the decryption key, known only to you, to view that data again.
If you only have a laptop and need more storage space then you can also get portable drives for extra storage of files you don't need all the time, i.e. pictures and videos, these take up the most space, these just plug into USB port on laptop, its like a GIANT USB stick, lol