When pruning fruit trees it is sometimes important to know where your fruit grows from on the tree so that you don't reduce your crop by incorrect pruning.  If you are wanting to espallier or cordon your apple then select a spur bearing variety. If you are wanting to train a step over then spur bearing is the type for this also but ensure you select M27 rootstock as most other dwarfing rootstocks are still too vigorous. 

See below for info on spur or tip bearing varieties.

The majority of apple varieties falls into this category, including well-known cultivars such as Coxes Orange Pippin and Egremont Russet. Most varieties of spur-bearing fruit trees yield fruit on three year old wood. In the second year, as the tip of each shoot extends to produce that season's vegetative growth, buds towards its base develop into fruit buds.

In the third year these buds will produce flowers which will go on to form fruit. In spur-bearing trees, fruit is produced on short, knobbly shoots called spurs that develop off the main branches.  Over time spurs develop into spur systems. Spur-bearers have a compact tidy appearance and fruit is distributed fairly evenly along the branch. This makes them suitable for restricted forms such as cordons and espaliers.

N.B. All pear trees are spur fruiting.

True or pure tip-bearing fruit trees are uncommon.  As the name suggests, fruit buds form on the tips of shoots.  When these shoots extend to produce the next year's vegetative growth, the buds at the tip of the previous year's growth develop into fruit buds. The buds at the base of the new season's growth remain dormant or form leaves.

It is important when pruning tip bearers not to prune off  next season's crop. The previous year's young shoots - maiden shoots - should be left to bear fruit the following year. However, shoots longer than 9 inches or so can be pruned back to a growth bud to stimulate the production of more short tip-bearing shoots that will produce fruit in two year's time.

In normal circumstances most trees thought of as tip-bearers actually produce fruit on the tips of young laterals as well as on spurs.  Bramley's Seedling, Discovery and Worcester Pearmain all fall into this category.  Partial tip-bearers can be pruned in the same way as spur-bearers, but this reduces the total yield.