Introduction to Computers and Programming

What is a computer program?

A set of instructions that a computer follows to perform a task.

What is software?

Programs that run on a computer; programs are commonly referred to as software.

Who creates computer software?

Programmers or software developers, who design, create, and test computer programs.

What is computer hardware?

The physical devices that a computer is made of.

What are the five main components of a computer system?

Central Processing Unit (CPU), main memory, secondary storage, input devices, and output devices.

What is the CPU?

The part of a computer that runs programs; it is often called the processor.

What happens if a computer has no CPU?

It cannot run software.

What does it mean to execute a program?

The computer performs the tasks that the program tells it to do.

What was ENIAC?

The world's first programmable computer.

When was ENIAC built?

1945.

What was ENIAC designed to calculate?

Artillery ballistic tables for the U.S. Army.

How large was ENIAC's CPU according to the lecture?

It was 8 feet tall, 100 feet long, and weighed 30 tons.

How does a modern microprocessor compare with ENIAC's CPU?

It is much smaller and much more powerful.

What is main memory?

The computer's work area where the running program and its data are stored.

What is main memory commonly called?

Random-access memory (RAM).

What is a key characteristic of RAM?

It is volatile memory used for temporary storage.

What happens to RAM contents when the computer is turned off?

The contents are erased.

What is ROM?

Read-Only Memory; a type of memory whose contents a computer can read but cannot change or add to.

Is ROM volatile or nonvolatile?

ROM is nonvolatile, so it does not lose its contents when power is turned off.

What is ROM typically used for?

Programs important to system operation, such as the computer's startup program.

What is secondary storage?

A type of memory that can hold data for long periods of time.

What is a common type of secondary storage?

A disk drive.

How does a traditional disk drive store data?

By magnetically encoding data onto a circular disk.

Why might an external disk drive be used?

To create backup copies.

What is a solid-state drive (SSD)?

A secondary-storage device that stores data in solid-state memory instead of on a disk.

What are two characteristics of solid-state drives?

They have no moving parts and operate faster than traditional disk drives.

What is a USB drive?

A small device that plugs into a computer's USB port and stores data on flash memory.

What are other names for USB drives?

Memory sticks and flash drives.

What are characteristics of USB drives?

They are inexpensive, reliable, and small.

How do optical devices such as CDs and DVDs store data?

Data is encoded as a series of pits on the disc's surface using a laser.

What are optical discs good for?

They can hold large amounts of data and are good for creating backups.

What is cloud storage?

Storing data on a remote server through the internet or a company's private network.

What is an advantage of cloud storage?

Data can be accessed from many devices and locations where a network connection is available.

What is input?

Any data the computer collects from people or from other devices.

What is an input device?

Hardware that collects data for the computer.

What are common input devices?

Keyboard, mouse, touch screen, scanner, microphone, and digital camera.

What is output?

Any data the computer produces for people or for other devices.

What is an output device?

Hardware that formats and presents data.

What are common output devices?

Monitor and printer.

What are the two categories of software?

System software and application software.

What is system software?

Programs that control and manage the basic operations of a computer.

What does an operating system do?

It controls the internal operations of computer hardware and manages devices connected to the computer.

What do utility programs do?

They perform specialized tasks that enhance the computer's operation or safeguard data.

What are software development tools?

Programs used to create, modify, and test software.

What is application software?

Programs people normally spend most of their time running to perform everyday tasks.

What are examples of application software?

Word processing, spreadsheets, databases, and presentation programs.

How is all data stored in a computer represented?

As sequences of 0s and 1s.

What is a byte?

A tiny storage location in computer memory; in the lecture, one byte represents one number.

How many bits are in one byte?

Eight bits.

What is a bit?

A binary digit; one of the eight smaller storage locations that make up a byte.

What can a bit represent?

A positive or negative electrical charge, corresponding to 1 or 0.

What does binary digit 1 represent in the lecture?

A positive charge or the switch's on position.

What does binary digit 0 represent in the lecture?

A negative charge or the switch's off position.

What is the binary numbering system?

A numbering system in which numeric values are written as sequences of 0s and 1s.

What is the largest value that can be stored in one byte of eight bits?

255.

What is the maximum value that can be stored using two bytes?

65,535.

How are characters stored in computer memory?

As binary numbers.

What is ASCII?

American Standard Code for Information Interchange; a coding scheme for characters.

How many numeric codes does ASCII have?

128.

What is Unicode?

An extensive encoding scheme that is compatible with ASCII and represents characters for many languages in the world.

How are negative numbers encoded?

Using two's complement.

How are real numbers encoded?

Using floating-point notation.

What is digital data?

Data that is stored in binary.

What is a digital device?

A device that works with binary data.

What are pixels?

Tiny dots of color that make up digital images; the term means picture elements.

What are samples?

Small pieces into which digital sound is broken.

What language can the CPU understand directly?

Machine language.

Why were other programming languages invented?

Because people find it very difficult to write entire programs in machine language.

What is the CPU designed to do?

Specific operations such as reading data from main memory, arithmetic, moving data, and determining whether values are equal.

What is a CPU instruction set?

The entire set of instructions that a CPU can execute.

Do all microprocessor brands have the same instruction set?

No. Each brand, such as Intel, AMD, and Motorola, has a unique instruction set.

What is the fetch-decode-execute cycle?

The cycle used when the CPU executes the instructions in a program.

What are the three steps of the fetch-decode-execute cycle?

Fetch, decode, and execute.

What happens during fetch?

The CPU fetches the next instruction in the program.

What happens during decode?

The CPU determines which operation the instruction specifies.

What happens during execute?

The CPU performs the operation specified by the instruction.

What is assembly language?

A low-level programming language that uses short words called mnemonics instead of binary machine-language instructions.

What is an assembler?

A program that translates an assembly-language program into a machine-language program.

What is a high-level language?

A language that lets programmers create powerful and complex programs without knowing how the CPU works, using words that are easier to understand.

What are examples of high-level languages listed in the lecture?

Java, C++, Python, Visual Basic, C#, Ada, and Fortran.

What are key words or reserved words?

Words that have a specific meaning and purpose in a programming language.

What are operators?

Symbols or elements that perform various operations on data.

What is syntax?

A set of rules that must be strictly followed when writing a program.

What are statements?

Individual instructions written in a programming language.

What is source code?

The statements written in a high-level programming language; also called code.

What is a syntax error?

A mistake such as a misspelled word, missing punctuation character, or incorrect use of an operator.

What is a compiler?

A program that translates a high-level-language program into a separate machine-language program.

What is an interpreter?

A program that both translates and executes the instructions in a high-level-language program.

What is the key difference between a compiler and an interpreter?

A compiler translates the high-level program into a separate machine-language program, while an interpreter translates and executes the instructions.

What are the two general categories of software?

System software and application software.