If your orange has no seeds it is likely a navel orange.
Although some other types of oranges may not have seeds which is normal.
Most oranges have seeds but it's normal for some oranges to have no seeds.
Seedless Fruit such as navel oranges are propagated asexually, usually by grafting.
The most frequent reasons for lack of seed development are pollination failure, or nonfunctional eggs or sperm.
Seedless fruit originated from genetic mutations that humans discovered and cultivated.
For example, seedless navel oranges date back to the 19th century and a single mutant tree in Brazil, whose progeny all come from buds grafted onto other citrus trees.
In the U.S., oranges are considered to be seedless if they have from zero to six seeds, according to Purdue University's Horticulture and Landscape Architecture website.
Because we view seeds as a nuisance when eating fresh oranges, breeders in the 1800s developed trees producing seedless varieties.
Generally, oranges, apples, and pears contain about 10 seeds.
Other fruits, such as avocados, plums, and peaches, have only one seed.
An orange is a fruit of various citrus species in the family Rutaceae; it primarily refers to Citrus × sinensis, which is also called sweet orange, to distinguish it from the related Citrus × aurantium, referred to as bitter orange.
Oranges are a good source of vitamin C, as well as several other vitamins, minerals, and antioxidants.
Some studies show that consuming citrus fruits like oranges on a regular basis may help lower the risk of certain health conditions, such as heart disease.