These are songs traditionally sung and learned by children in Primary. Primary songs are usually the same thing as children's songs, in the LDS church. All primary songs are children's songs, but not all children's songs are primary songs.
Primary songs are generally not sung by the congregation in sacrament meeting, unless they are included in the current hymnal (such as Teach Me to Walk in the Light, and I Am a Child of God). Others are, however, sometimes used for musical numbers in sacrament meeting.
There has been a definite refinement in the choice of songs in the more recent LDS children's songbooks. Many of the older primary songs do not seem to be suitable for church use today, however much they arguably may be suited to other occasions.
- This refers to such as Jolly Old Saint Nicholas, which was included in at least some old foreign language LDS songbooks (Himnos de Sión, 1942 and Hinos: Igreja de Jesus Cristo dos Santos dos Últimos Dias, 1965) containing both hymns and children's songs: many believe Santa Claus is a bad thing, due to the perceived tendency of people letting him taking preeminence over Christ during Christmas. Those who made certain songbooks, however, must not have yet perceived, or shared these views.