The video explains three ways to count cells or information in Google Sheets: using the Explorer, using the COUNT function, and using the COUNTALL function. The Explorer is a tool located at the bottom right of the screen that allows you to quickly understand your data and find the count of items in a column. The COUNT function allows you to count the number of cells that contain numbers in a range of cells, while the COUNTALL function counts all the cells in a range, including those that contain formulas or are blank. The video also mentions other functions such as SUM and UNIQUE