The "Next value in the trend" is calculated using the Trend1 function which uses the least squares method of generating a trend line and estimating what the next value along that trend line will be.
The "Trend value for Given 'X' " is calculated using the Trend2 funciton which uses the least squares method of generating a trend line and estimating the value along that trend line for the given 'X'.
The "Trend value for Current step" also uses the Trend2 function but uses a variable element ('Curent Step' which returns the current step) as the argument for which step value to show.
The "Dependent Value for given 'X' " is calculated using the Trend3 function which uses the least squares method of generating a trend line and estimating the value along that trend line for the given 'X'. It differs from the Trend2 function in that the dependency is to a series of values ("Independent array") which are not the steps in the model.
