A forecast is a prediction of the expected sales revenue of all the deals involved in a defined time frame. They are important for sales managers and, more generally, for the company's business people because they allow proper sales strategy planning.
Opportunities are the core source of data for forecasts because their amounts and quantities roll up over time, depending on their stages and other key data (such as close date, owner, products, and territory). Do you remember the Probability and Forecast Category fields on the Opportunity object? They are used in forecasts to segment and group opportunity data (no surprise that a 10% probability opportunity has a smaller impact on forecasts than a 90% probability one).
Change forecast categories values from Setup | Object Manager | Opportunity | Fields & Relations | Forecast Category to align...
