From what I've read so far, one the decision you have to make when interested in lighting work is either going with flashes or studio lights. Can we use both at the same time ?
Yes, you can use wireless triggers, sync cords, optical triggers, etc. to trigger both portable strobes and studio lights. If you are using (preflash) TTL instead of all manual, it will be slightly more difficult. You will have to attach the wireless triggers/sync cords to the controller. Or find optical triggers that ignore preflash.
There may be a difference in color that you should be aware of (e.g. to correct with gels).
When I read your question I think you're asking strobe/flash vs constant studio lights. If that's not what you mean, please clarify.
It's possible to mix them, but honestly to do so you need pretty powerful studio lights, and pretty weak strobes. Otherwise the amount of light put out by the strobes in the fraction of a second they fire is going to pretty much wash out any light from the studio lights as as to make it pretty much irrelevant as far as the final exposure matters.
Here's a case in point, this is the sooc image:
When I shot that there were two large softboxed strobes in front of her (basically I was shooting between them) and a third strobe with a grid overhead and camera right as a hairlight.
In the full sized 100% crop of her right eye, you can see the refelection of the softboxes pretty well, and almost make out the difference in the power levels (one was at 3/4 power, the other about 2/3 if I remember correctly... I had to turn them down so that the weaker strobe over head at full power gave enough light to the hair):
Additionally in the room, there was a fairly bright work light behind and camera left of her, that was our worklight so we could see between flashes. You'll note there is no hint of light from that side. In the 1/200th of a second the shutter was open, there wasn't enough light from that source to mater. (f/8, ISO 100 to complete the exposure data.) I looked through my cull pile from the shoot, but I can't find any shots that showed the effect of that light... I suspect the one that would have would be one where the radio popper failed and the strobes didn't fire... but that probably got deleted. What I recall seeing was that her right shoulder had a serious edge light and it cast a shadow onto her neck from her hair. That light would be about as bright as any constant studio lights I've ever seen, and it just didn't compete with the strobes.
(In case anyone is curious, here's the final shot after some TLC in LR.)