Comparing two versions of a webpage, email, or social media post (Version A and Version B) to see which one performs better. 

The invisible computer rules that decide which posts are shown to which users, usually prioritizing content that keeps people on the app longer. 

The raw data and statistics showing how your content is performing. 

The percentage of people who click a link to your website, look at one page, and immediately leave without doing anything else. A high bounce rate means your website is confusing or slow. 

When a user takes the exact action you wanted them to take (e.g., successfully donating, minting an NFT, signing a petition). The Conversion Rate is the percentage of total visitors who completed that action. 

Data about the people in your audience (age, location, gender, language). 

The main feed on TikTok (and similar to Instagram Reels) where the algorithm shows content to people who do not follow you yet. The holy grail of organic discovery. 

The primary metric you choose to define success for a specific goal. (e.g., If your goal is fundraising, your KPI is "Total Dollars Raised," not "Instagram Likes"). 

Data extracted directly from the blockchain (e.g., tracking the number of unique wallets holding an NFT, or viewing transaction history transparently). 

The measure of what you got back compared to what you put in. If you spend $50 on Meta Ads and raise $200 in donations, you have a positive ROI.