This does not mean that a pope as an individual decides that something is to be considered true which had not already been held to be true by the faithful. But he is simply declaring, at some particular time of need or of controversy, that such a teaching is truly an authentic part of the deposit of faith. Or this can be done simply in response to a desire expressed by the faithful in regard to a truth which has already been believed. He is stating that such a truth has been taught, at least in principle, by Christ himself through the apostles. The truths of faith and morals remain always the same.
New insights add precision but never eliminate truths from the deposit of faith.
These truths, recognized as such, or not, are meant for all people. They are to be believed by all Catholic Christians here on earth, and most surely are acknowledged by all those in heaven. These truths are the word of God, which he has freely revealed to us, especially through his Son Jesus Christ, the Word of God become man. The verbal word of God in its written or oral form has been preserved, for all generations, both in the Scriptures and in the teaching form which has been handed down orally, so-called Tradition. The task of authentically interpreting the word of God has been entrusted exclusively to the living teaching office of the church.