RNA velocity is based on bridging measurements to a underlying mechanism, mRNA splicing, with two modes indicating the current and future state. It is a method used to predict the future gene expression of a cell based on the measurement of both spliced and unspliced transcripts of mRNA.
RNA velocity could be used to infer the direction of gene expression changes in single-cell RNA sequencing (scRNA-seq) data. It provides insights into the future state of individual cells by using the abundance of unspliced to spliced RNA transcripts. This ratio can indicate the transcriptional dynamics and potential fate of a cell, such as whether it is transitioning from one cell type to another or undergoing differentiation.