For a vector field to be covariantly constant at a point in a curved space, it is mandatory that theRiemann-Tensor is also zero at that point. Thus, in the presence of curvature, we cannot define a vector corresponding to the field at the point by looking for a covariantly constant vector. Instead, we consider a curve and then define a vector field to be covariantly constant along the curve or parallel transported along the curve if The way vectors change under parallel transport around arbitrary closed loops is one way to characterise the curvature of a space -Holonomy