Nesting is more or less just putting one or more if statements in another if statement. To visualize is in a more understandable way I found this graphic:
Furthermore I will show you an basic example of nested if statements. The Program wants to find out if the chosen variable, in this case 100, is smaller then 200, equals 150, 100, 50 or less then 50. If none of those statements become true, it will put out a string.
Example:
If executed:
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