Changes to a substance that do not involve a permanent reordering of atoms are known as a

Physical Change.

There are two main types of change called physical and chemical change.
So basically as you probably guessed chemical change generally involves heat and once the change has taken place a new substance is formed and cannot be changed back to the original substance.
Ex Burning paper to ash.
Ash is a new substance and it involves heat.You also can’t change it back to paper.

Now Physical changes sometimes also involve heat and no new substance is formed.It can be changed back to the original substance.There are no major chemical changes happening hear.It is essentially what the above definition says.It does not involve permanent reordering(changing) of atoms.
This means it can be changed back.

Hope this helps:)

Change in speed or direction : )