At the time of this post 7805 will bring up 2651 items because the short part number is incorporated in so many other product numbers.
If your part is not one of the 3 parts that come up as exact matches then you will need to know a little more about your part.
When doing a internet search I see a 5V voltage regulator that is a popular result.
If I choose that category and my output voltage I have narrowed the results considerably. The next concern if I am doing a repair is to match the package/case if I know I am looking for a through hole TO220-3 size I can select that and apply filters again.
Since this is a popular part and is manufactured by multiple manufacturers I still have to make some decisions but it is a lot easier to manage Click here to see my results.