HTML

• The head element contains information about the webpage.
• The body element represents the visible content shown to the user.
• Elements that are nested inside other elements are called child elements.
• The element that holds all the children is known as the parent element.

CSS

• A margin indicates how much space we want around the outside of an element.
• A padding indicates how much space we want around the content inside an element.
• Assigning colors in CSS can be done in many ways, including by semantic references such as gray or blue. We can also refer to a color by its hexadecimal code, or hex #.
• box-shadow CSS property adds shadow effects around an element's frame.

Git

• git status: checks what branch we are currently on
• git checkout -b branch-name: creates a new branch and switches to it
• git add -A: The add command adds modifications in the current working branch to the staging area. The -A flag indicates that we want to add all changes. The staging area informs Git that the changes will be added in the next commit.
• git pull origin: receive a branch's modifications into the local environment

JavaScript

• A variable is a named container that allows us to store data in our code.
• Control flow is the order in which a computer executes code in a script.
• An if statement is a way of introducing decision-making into our code. Just like its name sounds, when using the if statement, code will only execute if the statement meets a condition, or is true.
• An array is a single variable that is used to hold a group of data. Arrays are typically used to hold data that is related in some way.