The Asus Zenfone AR uses the second version Universal Flash Storage UFS 2.0, which is according to Samsung official website, is three times faster than eMMC 5.1 and was designed to match the performance need of high-end mobile devices. The Asus Zenfone AR needs it mainly for its Tango feature, because it needs fast access to read texture data. I've also read on Samsung's website that UFC technology is much more power efficient with 35% total system power saving compared to eMMC in daily workload performance.
Of course UFS is beneficial not just to Tango-enabled operations, but is essential to match the requirements needed for multitasking, high-resolution video recording (i.e. 4k and even 8K when it becomes available in mobile devices) and for all applications that require a higher bandwidth for apps that consume big data from the built-in storage. It's like having your own small SSD harddrive inside your smartphone but with the benefits of eMMC technology which is optimized for mobile. You can expect results like having a SSD in your computer, with faster application load times, improved multi-tasking jobs, better burst shot using the built-in camera (images can be written much faster from the memory into the storage device), photo thumbnail loading time is significantly increased, etc. Compared to eMMC 5.0 which has a Parallel interface Half Duplex (only either reading or writing at the same time), UFS 2.0 is also Full-duplex, so both the storage device and the receiver can transmit and receive information at the same time, which boosts the multitasking performance by a large margin.
UFS 2.0 enjoys the benefits of SSD and eMMC technology. It borrows the High speed serial I/F, command queue and SCSI architecture of the SSD and from eMMC it borrows the low power usage, the flash oriented features and its mobile optimizations. Both read and write are faster in the UFS2.0 compared to eMMC5.0.
Here is a video by Samsung that shows how UFS benefits the user:
By the way, according to this article on bgr.com, the iPhone 6s uses a NVMe protocol with custom NAND memory shown much faster performance than the Samsung Galaxy S6 in sequential write and read tests, but Samsung did improve the performance of its UFS 2.0 drives and according to the charts from Anandtech that you see in that article, the performance was indeed improved in the Samsung Galaxy S7, but it's still behind the iPhone 6s Plus performance. Samsung will improve the performance of its technology in the upcoming years, so it would be much faster. HTC 10 uses the Embedded Multi-Media Controller (eMMC) 5.1 NAND memory, which results in significantly lower read/write performance. The Samsung Galaxy S7 edge and LG G5 both utilize the UFS technology and therefore results in a much faster sequential and Random Read performance. It doesn't mean that the HTC 10 is slow by any means but this is something that HTC needs to improve in its future phones.
So all in all,I thought it's important to mention this storage technology advantage. The ZenFone AR comes with four internal storage variants: 32GB, 64GB, 128GB and 256GB and all of them use UFS 2.0 technology.