Is the following graph a distance-time graph with uniform or non-uniform velocity?

Uniform velocity refers to the fact that identical displacement happens at equal time intervals. The item travels in a definite direction in this case. 

Non-uniform velocity: This occurs when uneven displacement occurs in the same time interval. It is sometimes referred to as fluctuating velocity.

When a body travels the same distance in the same amount of time, it is said to have uniform velocity.