There is probably a loose or broken cable, most likely connected to the hard drive
It should work unless you did or bought the wrong thing
When using a public computer or network, you should always browse appropriately and log out of personal accounts when you're done.
Answer:
Data is stored in tables, where each row is an item in a collection, and each column represents a particular attribute of the items. Well-designed relational databases conventionally follow third normal form (3NF), in which no data is duplicated in the system. ... With a homogenous data set, it is highly space efficient