In harry potter what exactly is this smoke travel used by the wizards if not App!

In harry potter what exactly is this smoke travel used by the wizards if not Apparition?

After watching HP and the order of the phoenix one question sticks in my mind. bear with me cause I need to set the question up bit.

In book 4 after the dark mark was created ministry officials appeared all around Harry and company.

In movie 4 this was shown by the ministry officials traveling in smoke.
I like many of my friends assumed that that was the way they chose to represent apparition.

Now in movie 5 it clearly shows the weasley twins appariting twice in the headquarters….. With no smoke.

Later on in movie 5 it again shows for lack of a better term “Smoke Travel” during the battles in the ministry.

My question is what exactly is this smoke travel if not Apparition?

2 weeks ago
After watching HP and the order of the phoenix one question sticks in my mind. bear with me cause I need to set the question up bit.

In book 4 after the dark mark was created ministry officials appeared all around Harry and company.

In movie 4 this was shown by the ministry officials traveling in smoke.
I like many of my friends assumed that that was the way they chose to represent apparition.

Now in movie 5 it clearly shows the weasley twins appariting twice in the headquarters….. With no smoke.

Later on in movie 5 it again shows for lack of a better term “Smoke Travel” during the battles in the ministry.

My question is what exactly is this smoke travel if not Apparition?

** Added **
It is not floo powder! i know what floo powder is and this is deffenatly something diffrent

I do not think it is floo powder as that is always green - even when Dumbledore comes in at the end, his smoke is green. I think it is the "evil" interpretation with the black masks, cloaks and then the black smoke. If you remember, when Sirius, Tonks, Lupin, etc came in - their smoke was white. So I think it shows us good vs. evil by using the smoke color. Also, it might not truly be "smoke", but portrayed as such to show how fast experienced wizards can move where it is a blur (like smoke). When the Weasleys apparited, they are just getting started and just went from point A to point B: there one minute, somewhere else the next.