That is the Gift of Tongues. As we read Acts, Corinthians, and Romans, it is clear that there are two different types of ‘tongues’.
Paul says that a message in tongues with interpretation (in the church) should be no more than three. Here is Paul’s description of the gift at work in an early church assembly…
I Cor 14:26-33 *26 What is the outcome then, brethren? When you assemble, each one has a psalm, has a teaching, has a revelation, has a tongue, has an interpretation. Let all things be done for edification. 27 If anyone speaks in a tongue, it should be by two or at the most three, and each in turn, and one must interpret; 28 but if there is no interpreter, he must keep silent in the church; and let him speak to himself and to God. 29 Let two or three prophets speak, and let the others pass judgment. 30 But if a revelation is made to another who is seated, the first one must keep silent. 31 For you can all prophesy one by one, so that all may learn and all may be exhorted; 32 and the spirits of prophets are subject to prophets; 33 for God is not a God of confusion but of peace, as in all the churches of the saints.
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The second type is observed in Acts 2:4, Acts 10:44-47, Acts 19:1-6, and is discussed by Paul in 1 Cor 14 too.
I Cor 14:14 *14 For if I pray in a tongue, my spirit prays, but my mind is unfruitful. 15 What is the outcome then? I will pray with the spirit and I will pray with the mind also; I will sing with the spirit and I will sing with the mind also. *
Remember, it is Paul that also wrote: I Cor 14:18 * I thank God, I speak in tongues more than you all* and I Cor 14:39 Therefore, my brethren, desire earnestly to prophesy, and do not forbid to speak in tongues.
The difference between the Gift of Tongues and the Prayer Language is that all do not have the Gift of Tongues (message with interpretation) but that all CAN have the prayer language as a result of th Holy Spirit’s work. One is from God to Man (the message with interpretation) and the other is prayer from Man to God as the Spirit gives utterance. Similar, but operating in two different directions with different purposes.