Syrup (from Arabic Sarab, siropus via Latin) is a thick, concentrated liquid with lots of sugar (sucrose). It has long been used to sweeten meals. In the Low Countries it’s called ‘stroop’, is thick and sticky while syrup is fuid.

A traditional apple butter is made of apples and / or pears​​.
By adding pears a higher sugar content can be achieved.
The high sugar content gives it, cut off from air, long shelf life without refrigeration.
10 to 20 kg of fruits are good for 1 liter of apple butter.
Cook the fruit. Press the mass in jute cloths, which hardly clog. Allow to thicken by cooking. Stir frequently over the bottom to prevent burning. (It should become as thick as cold, hard grease, or caramel.)
If the thickened juice contains enough sugar the apple butter will keep for several years.
To avoid burning also a layer of sugar beets was placed on the bottom of the kettle at the start.

The word syrup is commonly used for thinner syrups (e.g. lemonade, or to make lemonade).

Juice of the famous Canadian maple is (as birch here) drained. It is boiled and concentrated in order to get a syrup to sweeten. The juice contains 2.5% to 5% sugar. There can be extracted 20 to 25 liters per tree.