What's the different between words "gap" and "crack"?

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https://www.etutor.pl/szukaj/?q=gap&x=101&y=15&mode=DICTIONARY
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gap
1 różnica
+ between
the widening gap between rich and poor
There’s a big age gap between them.
2 szpara
+ in/between
The cat escaped through a gap in the fence.
Dave has a big gap between his two front teeth.
3 luka
+ in
When my wife left me, it left a big gap in my life.
4 przerwa
+ in
an uncomfortable gap in the conversation

crack jako czasownik
1 [I]
po/pękać
The ice was starting to crack.
2 [T]
zrobić rysę w
I dropped a plate and cracked it.
3 [T]
rozbić, rozłupać
The fox cracked the egg and sucked out the yolk.
4 [T] informal
rozgryźć (problem)
Yes! I’ve finally cracked it!
5 [I]
załamać się
She was beginning to crack under the strain of trying to do two jobs.
6 [I,T]
trzaskać
He cracked his knuckles.

crack down phr v [I] brać/wziąć się ostro za
+ on
The government plans to crack down on child pornography on the Internet.

crack up phr v [I] informal
1 przechodzić załamanie nerwowe
I’m worried about Lisa – I think she’s cracking up.
2 not all it’s cracked up to be
(wcale) nie taki wspaniały, jak się wydaje
Life as a model isn’t all it’s cracked up to be.

crack jako rzeczownik
n
1 [C]
rysa, pęknięcie
A huge crack had appeared in the ceiling.
2 [C]
szpara
a crack in the curtains
3 [C]
trzask
The firework exploded with a loud crack.
4 [U]
crack (narkotyk)
5 at the crack of dawn
skoro świt
We had to get up at the crack of dawn.

i crack (adj) pierwszorzędny
crack troops (=elitarne jednostki)
a crack shot (=wyborowy strzelec)

gap-przerwa, luka
crack- pęknięcie, rysa