This script calculates high/low pivots for different timeframes (daily, weekly, monthly, quarterly, and yearly). You have various pivot point calculation methods (Traditional, Fibonacci, Woodie, Classic, DM, Camarilla) and have inputs that allow customization of the indicator. The script also accounts for custom year-based calculations (bi-yearly, tri-yearly, quinquennially, decennially).
The first part of your code calculates the high and low levels for different timeframes, which are plotted on the chart as crosses. The second part involves the pivot point calculations, where the user selects the type of pivot point calculation (Traditional, Fibonacci, etc.), the timeframe for pivots, and other display settings.