Unit 3 Vocabulary

Python and the Terminal

Python

A text-based programming language used widely in artificial intelligence, data science, and web development.

Terminal

An app for controlling a computer by typing text commands instead of clicking.

Command Line Interface (CLI)

Any text-command way of using a computer. The Terminal app, the VS Code integrated terminal, and the Minecraft / chat are all CLIs.

Graphical User Interface (GUI)

A point-and-click way of using a computer, with windows, icons, and menus.

Directory

Another word for a folder. cd changes directory; ls lists what is in one.

Script

A file of code that runs from top to bottom. Python scripts end in .py.

IDE

Integrated Development Environment — an app for writing and running code. VS Code is the one we use.

Library

Pre-written code you can install and use in your own program. pandas and matplotlib are libraries.

input()

A Python function that pauses the program, waits for the user to type something, and hands it back as text.

while loop

A loop that keeps repeating as long as its condition is true.

if / elif / else

Python’s conditional. elif (“else if”) adds another condition to check when the first one is false.

Data

Data

Information stored in a form a computer can work with — usually numbers, words, or both.

Dataset

A collection of related data saved together, often in one file.

CSV

Comma-separated values. A plain-text table: one record per line, columns separated by commas.

DataFrame

A table of data in pandas. By convention the variable is named df.

Mean

The average. Add every value, then divide by how many there are.

Median

The middle value when the numbers are sorted from smallest to largest.

Distribution

How often each value shows up in a dataset. A histogram is a picture of a distribution.

Histogram

A plot that groups one number column into ranges and shows how many values fall in each.

Bar Chart

A plot that compares counts or totals across categories.

Scatter Plot

A plot where every record is one dot placed by two number columns, used to see whether the two are related.

Box Plot

A plot that shows the typical range of a column — the middle half of the values as a box, with the median as a line.

Outlier

A value far outside the typical range.

Artificial Intelligence

Artificial Intelligence (AI)

Software designed to do tasks that normally require human thinking, like recognizing faces, understanding speech, or recommending videos.

Machine Learning

A way of building AI where the computer learns from examples instead of following rules a programmer wrote line by line.

Training Data

The collection of examples used to teach a machine learning model. For an image classifier, each example is a photo labeled with the right answer.

Class

A category a model learns to recognize, such as Rock, Paper, or Scissors.

Model

The result of training — a set of learned patterns the computer uses to make predictions about new input.

Confidence Score

A percentage that tells you how sure the model is about a prediction.

Epoch

One complete pass through all the training examples.

Bias (in AI)

When a system’s results are systematically unfair, often because the training data over-represented or under-represented certain groups.

Hacker

Someone who finds ways into computer systems. Ethical hackers do it with permission to find and fix weaknesses; malicious hackers do it to steal or damage.