Is there a difference of a lilac bush from a lilac tree?

It appears to have been cut and trained into a tree.

This is a Miss Kim Lilac that is different from the lilacs our grandmothers had. They are slow growing and have a more intense smell. They do not do well indoors as cut flowers. If you want to prune do so just after they bloom

Shrub Lilacs and bush lilacs are short and compact. Tree lilacs are trickier. The classic definition of a tree is that it is over 13 feet tall and has a single trunk. Tree lilacs can grow up to 25 feet high and have a tree-like appearance, but their many stems tend to get them classified as bushes.

It looks like a dwarf Lilac tree..which grows 5' tall & 6' wide..I have one..

That is a Miss Kim or Meyer lilac that has been grafted to a standard trunk. This may sucker at the base .

Lilac bushes sucker and are harder to control. Trees are more clean looking and easier to maintain. Bushes make for more privacy or hedge looking though.

I have a French lilac bush that looks the same. Would like to know how to trim it so it looks like the one in the photo.

Dwarf Korean Lilac = Syringa Meyeri Palabin. They are not dwarf trees. They are shrubs that can be grafted onto a tree base so they look like a tree but they are actually a shrub growing on top of a tree trunk. If you look carefully you can often find the graft. They are also used (on the ground )as hedges in many places. They have a lovely fragrance.

Is a Graft something you can purchase at a lawn store? How soon should you start to use it, I don't want to hurt the bush that was just planted.

I have inherited an old Lilac Tree which has a lot of dead wood in it if I cut it back hard I won’t lose it will I, I realise I probably won’t get any blooms for awhile but I don’t know hoe best to treat the tree?

I have a Lilac tree outside my door. It may flower once a year if I'm lucky but more often I'm looking at an empty tree. I prune off the blooms as soon as they are spent and prune if I have to right before winter sets in. It;s in a sunny corner. with partial shade it just rarely blooms. I did lnotice it has many thick branches instead of one like a tree, are these little suckers draining away all the blooming energy?

A Lilac Tree AKA Persian Lilac AKA Indian Lilac AKA White Cedar AKA Chinaberry Tree, is altogether a completely different plant than the Lilac Shrub, the flower is smaller and the smell is much much nicer, like an expensive perfume, in comparison to the funky smelling shrub version.