Summary of Session 1: Jargon!

bit = "binary digit" = a 0 or 1
- the smallest unit of data that a computer can process/store
byte = 8 bits = 1 character (on a US keyboard)
- megabyte (MB) = 1 Million bytes (technically it's 2^20 = 1,048,576 bytes
- gigabyte (GB) = 1 Billion bytes (2^30 = 1,073,741,824 bytes)
- terabyte (TB) = 1 Trillion bytes (2^40 = 1,099,511,627,776 bytes)
CPU = Central Processing Unit = "brain" of a computer
- it's a super fast, super dumb brain
- it can do billions of operations per second
- ...but each operation is pretty simple
  - moving data from memory into the CPU
  - storing data in the CPU into memory
  - integer arithmetic (e.g., 2 + 3)
  - floating point arithmetic (e.g., 2.3 * -5.1)
  - branching ("jump" to a different place in the code)
RAM = Random Access Memory (or just "memory")
- space the computer can work with while it's turned on (e.g., applications live in RAM when they are running)
- 16 GB RAM = 16 Billion bytes or characters worth of "work space"

What is an executable/program/application (e.g., Google Chrome)?

a series of instructions in a language that the CPU understands
- that language is called "assembly language" or "machine language"
applications (runnable code) are stored on your hard drive, just like any other file
when you double click (or otherwise launch an application)
- the OS (Windows, Mac, Linux) loads the application into memory (RAM)
- the CPU begins running it
  - that is, the CPU decodes each instruction and does what it is told
  - instructions are of two types
    - load/store = move memory to/from the CPU
    - operational = arithmetic or other operations on the data in the CPU

a process that begins with the formulation of a (computing) problem and ends with the creation of an runnable computer program
a program is a set of statements or instructions that tells the computer what to do
in order to write a program, programmers often begin with an algorithm
- an algorithm is a set of rules to be followed to solve a problem (usually, but not always by a computer)
  - e.g., an algorithm for converting Fahrenheit temperatures into Celsius:
    - subtract 32 from the Fahrenheit temperature
    - multiply the result by 5/9
pseudocode is a notation resembling a simplified programming language
- it's often a mixture of English and real programming language constructs
- we will always write pseudocode BEFORE writing any code
- you will want to jump right in and code w/o writing pseudocode...just don't
  - otherwise you will end up with a non-working program with no understanding of how you got there!
- every line of code you write as a purpose and you should be able to relate that purpose back to the pseudocode or steps that you previously wrote down