Answer 1

Lambdas are like "anonymous", one-time, one-purpose methods, which do not require proper defining.
If you don't need to use a function/method multiple times in your code, you can use lambda. The syntax is awfully simple:

print((lambda x: x**2)(10))

Anonymous lambda function taking x as argument, returns the square of x - and you give it 10 as argument. The output result is...
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100, of course :)