When sound is sampled at a low rate:
There is a poor match between the original sound and the sampled sound
Small file size is required
Very few samples are taken
The data stored includes the audio codec and the sample rate
Sound is an analogue form so to transfer sound to a computer it needs to be digitally sampled
Sound files are described by metadata to make sure the computer can interpret the data accurately
Magnetic hard disk
Hard disks are:
Optical disks are:
lightweight and portable
Is excellent for transferring files or distributing software
Stores the operating system, installed programs and user data
Tables appear in print media, handwritten notes, computer software, architectural ornamentation, traffic signs, and many other places
Tables are widely used in communication, research, and data analysis
A table is an arrangement of data in rows and columns
a set of data that describes and gives information about other data.
has become increasingly important in XML-based Web applications
Metadata describes how and when and by whom a particular set of data was collected, and how the data is formatted.
Metadata can be created manually, or by automated information processing.
One hexadecimal digit represents a nibble (4 bits), which is half of a byte (8 bits).
Hexadecimal is a convenient way to express binary numbers in modern computers in which a byte is almost always defined as containing eight binary digits
is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F (or alternatively a, b, c, d, e, f) to represent values ten to fifteen.
primary and foreign keys
In a foreign key reference, a link is created between two tables when the column or columns that hold the primary key value for one table are referenced by the column or columns in another table. This column becomes a foreign key in the second table.