There are five Heian forms, containing a great variety of techniques and almost all of the basic stances. Having mastered these five forms, one can be confident that he is able to defend himself competently in most situations. The meaning of the name is to be taken in this context.
The kata Heian Nidan emphasizes simultaneous defense and offense, attacking and defending.
"At one time, this form was Heian Shodan. There are twenty-six movements to be completed in about one minute. The comments in the discussion of Heian Shodan concerning the bows, and Yoi apply here as well. The line of movement is of the I type as in Heian Shodan."