UltraEdit maintains a rotating list of positions that you last edited, changed position from, or jumped to another file from with the Find symbol command. This allows you to quickly jump back to a previous position or file after changing position within a file, or to another file.
The Back command repositions the cursor to the previous position/file in the list. When you jump back, the Forward command is enabled so that you can navigate forward again to the position you just came from.
When a change is made, or a repositioning of the caret occurs that updates the list of remembered positions, the new position is added to the list at the current list position. This enables you to continue to navigate forwards/backwards as desired.
When editing within a file, only the last edit position is remembered since the last reposition; not every position for each character added or change made in sequence is remembered.
UltraEdit Wiki