Delta-10 or Delta 10-Tetrahydrocannabinol is one of the many cannabinoids, just like Delta-8, from the hemp plant (and cannabis plant). Delta 10 is becoming more and more popular and you can find Delta-10 in the market through the forms of gummies, vapes and cartridges.
Delta-10 is considered legal in accordance with the 2018 Farm Bill as it is derived from hemp and containing less than 0.3% of delta-9 THC.
12 States where it is not allowed to buy Delta-10: Alaska, Arizona, Arkansas, Colorado, Delaware, Idaho, Iowa, Mississippi, Montana, Rhode Island, Utah, & Washington.
You must be 18 years or older to buy Delta-10 THC.
It is a natural compound but is considered to be semi-synthetic as it needs an isomerization to get enough.
Delta 10 is said to be less intense than delta 9 or delta 8 and it will not give you the paranoia nor anxiety that delta-9 can give you. Delta-10 THC will get you high though and should fail a drug test.
There is not enough evidence of whether it has side-effects but consuming too much could cause nausea, vomiting, paranoia, dry mouth, red and itchy eyes, psychoactivity, or increased appetite. Always start with a low dose and read the labels for instructions and particularly do not drive nor operate heave machines after consuming delta-10.
There is not enough research neither on the benefits of delta-10 but there should be promising results.

Difference with delta-8
Delta 8 has a stronger effect on the ECS receptors, as it binds better to CB1 and CB2 receptors of the brain. This is one of the reasons why delta 8 is stronger than delta 10
Delta-8 has an indica effect (relaxation and for increasing appetite) whereas Delta-10 gives a sativa effect. This means that it supports creativity, productivity, energy and alertness. As such Delta-10 tends to be more of a daytime product.