What is the difference between Total Long Term Debt and Net Total Long Term Debt?
Below you can see a picture revealing that they are not equal.
Net Debt = Total Debt - Cash
You can also see from the graph, that Net Debt is always below Total Debt.
Cash (and liquid marketable securities) is deducted from Debt, because it could be in theory directly used to repay the debt, hence only "Net Debt" is important; think a company with 1mio Debt and 1mio Cash, one would not say it was in debt because it can essentially repay any time.