Data is stored in tables. A table represents a list of things, for example all the products you sell, all your contacts or every transaction you've completed. Any kind of data can be stored in a table.
A table is a collection of rows and columns, much like a spreadsheet datasheet. A row (also called a record) represents a thing, for example the people: John, Brooke and Edward. A column (also called a field) represents the attributes of these things, for example their Names, Addresses or Phone Numbers.
Tables are created and can have their structures modified in Table Design view. You can read more about table design view here:
Once a table has been designed, it's time to add data to it. You can do this in either Table Data view or Form view. Table Data view shows data in a tabular format, like a spreadsheet. Form view shows data as a series of text fields and other controls.