Clarity needed regarding scaling, standardizing, a normalization:

Hi,I have couple of doubt regarding scaling, standardizing, a normalization:

when to use log transformation ?
When do we need to transform the skewed columns in the data ?
how to transform left skewed data to normal distributed data ?
after transforming data with log transformation do we require to do scaling /standardization?
what are the algorithms which require data to be normally distributed ?
while performing scaling/standardization do we need to scale/standardization all the numerical features in the data ?
when to perform normalization and when to perform standardization ?
Does transforming or scaling change the characteristics of data ?

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