Difference between load, with, local variables,refresh variables

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All 4 functions are used to declare local variables. load local varibales gets initialized when page loads and updated
on save into of a button, with variables will be refreshed when local variable declared in with variable's defination
changes its value ex: local!with : local!load +1, local!with's value changes whenever local!load changes.

a!localvariable replaces load and with where local variables can be defined inside a!localvariable function and a variable can be configured as refreshvariable using a!refreshvariable, by this way of defining variables it gives more flexibility to  developers to control when a variable will be refreshed configureing the parameters : refreshAlways, refreshInterval, refreshOnReferencedVarChange, refreshOnVarChange & refreshAfter.