sequence: this is the part of the algorithm that moves through a set of data, a for-loop or while-loop is an example of this.

selection: this is the part of the algorithm that actually selects the next step based on the true or false conditional (if-else) is an example of this.

Iteration: this simply mean to "repeat". So any part of the algorithm that causes it to "loop" -if statement, for loop, while loop are all examples.