As you already know, uniform motion (MU) is one where velocity is constant and non-zero.
The characteristic equation of uniform motion (MU) is:
y = y0 + vt.
Depending on the direction of movement, it can be classified as: Progressive Movement or Retrograde Movement.
progressive movement
The progressive movement is the one in which the mobile moves in the same direction as the trajectory orientation. Here, spaces grow along the route as a function of time.
In progressive movement, the scalar velocity is positive. (v>0)
retrograde movement
The movement is called Retrograde when the rover moves against the trajectory orientation. Its spaces decrease over time and its speed is negative. (v < 0)
In practice, there is no negative velocity. The speed sign serves only to indicate the direction of movement and to say whether the movement is progressive or retrograde.
By Kléber Cavalcante
Graduated in Physics
Brazil School Team
mechanics - Physics - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/fisica/movimento-progressivo-movimento-retrogrado.htm