There are two types of technical indicators in thinkorswim: studies and strategies (not taking into account the multitude of the pre-defined patterns, as there is a separate section in the manual dedicated to these). Studies are technical indicators that calculate certain values for each bar on chart. Strategies, on the other hand, also provide you with historical trade signals: time and price points on chart where a certain price-based condition was satisfied. Strategies can also be back-tested: you can view a report that calculates the hypothetical profit/loss value that could have been actual if the signals given by the strategy were real buy and sell orders.