When using a breadth or depth first search algorithm in a tree search, how do you know which is better to use out of the two?

Question

Does it depend on the structure/width of the organised data tree?

Answer 1

It depends on your scenario.
Typically both have more-or-less the same time complexity

Answer 2

Breadth first search is more efficient... when compared to depth first search

Answer 3

You should look into big O notation. It gets into how to figure out how much time complexity certain algorithms have.
MIT has a free corse on YouTube from 2011 I believe. I have currently been going through it and taking notes. Should be called MIT 6.006 on YouTube.