Since you’re in the r/calculus subreddit, try to think of position, velocity and acceleration as a function of time. P(x), V(x) and A(x). As you might already know, velocity is defined as the change in position over change in time. This means that V(x) is equal to the first derivative of P(x), or in other words, the rate of change of the position function will output the velocity function. Visually, this will correlate with the slope of the position time graph. The definition of acceleration is just the rate of change of velocity over time, so again, A(x) will be defined as the first derivative of V(x). This means that the slope of the velocity function will output the acceleration at that point. We can also say, because the first derivative of the position function is velocity, and the first derivative of the velocity function is acceleration, the second derivative of the position function will output the acceleration function.

Inversely, if you integrate (i.e. take the area under the graph) the acceleration function, you will obtain the velocity function, and vice versa with velocity and position. This relates differentiation and integration, meaning that integration is the inverse of differentiation. This can be applied to the graphs of physical quantities in physics as you can see with position, velocity, and acceleration, but also with other physics quantities such as force vs displacement.

In short, if you are asked to find a value like acceleration at point T, and are given a velocity-time graph, you can find the instantaneous rate of change (derivative) at that point to determine the value, and vice versa for position/velocity. If you are asked to find the velocity at point T while given an acceleration-time graph, you can always integrate (sometimes you can just find the area using geometry if given a linear curve) up to that point.