do they still use flaks

If you mean anti-aircraft guns, yes. But only the lighter ones for low level point defence. For mid to high altitude the large guns have all been replaced by missiles.

The word ''flak'' is always singular; there is no such thing as ''flaks.''

''Flak'' is a slang expression for altitude activated anti-aircraft explosive shells. Anti-aircraft artillery used these to force bombers to fly high and so make bombing less accurate.

Anti-aircraft artillery is still in use, but surface-to-air missiles are more common now, as they are more accurate and more efficient in the use of war materials.

Actually, ''flak'' is not slang. It is a German acronym from World War 2. ''Flak'' stands for ''FLiegerAbwehrKanone or literally, ''aircraft defense gun''.

Probably the most impressive example for modern day flak is the automatic, radar controlled Phalanx system used on US aircraft carriers against missiles rather than aircraft.

In short yes, though the term ''flak'' is now anachronistic ''Anti-Aircraft Artillery'' = ''AAA'' is the preferred term:
20mm, 23mm, 30mm, 35mm, 40mm & 57mm AAA is still prevalent. Not to mention small arms in the 7.62-14.5mm range. The majority of downed aircraft in the Vietnam & '67 wars were shot down not by SAMS or in air/air but by AAA.
It is cheap, easy to use & reasonably effective against lowflyers: Helos, UAVs, cruise missiles & fast movers in a low altitude delivery. Something common to all ground based air defenses is that forcing the attacker to jettison stores to maneuver, etc r ''mission kills'' & r almost as good as a direct hit.

YES. Flak is still around.

2m6 (?) tunguska
ZSU 23-4 Shilka
ZSU 57
ZPU various platforms
the Vulcan mount on the M-113 /withdrawn from AA duties now
various ship born systems
Gepard


Yes the anti aircraft artillery is still around in most battlefields. it is usually dual used as infantry support weapon.
he towed systems r no longer extensively used. they happend to be obsolete once the battlefield went mobile - the artillery pieces needed to follow the supported arms

Yes they do and the weapon size varies greatly. they do not make the large Flak guns of WW2 any more. The biggest modern guns are 5'' guns on warships. The largest land based guns l think are in the 57mm range. Missile systems like the patriot system do the work old flak guns used to do.