New to apple trees I have a leaf question

[tooln]

When you guys talk about 2nd or 3rd leaf trees. What does this mean?

 

[leexrayshady]

Number of years in the ground, planting year is 1st leaf.

 

[tooln]

OK that makes sense. Thanks

 

[leexrayshady]

Can get confusing, when one guy has a three year old nursery tree and another has a 1 yr. But both planted in final spot in same year and both 1st leaf