What is the differences between apostolic and pentecostal?

Pentecostalism is an umbrella term used in order to refer to groups that came from the early 1900 Azusa Street Revival. Of these groups, the two major terms include Oneness Pentecostals and Trinitarian Pentecostals. Oneness Pentecostals are often referred to as "Apostolic Pentecostals", which is a way used to define their doctrinal beliefs in the Oneness of God and the Acts 2:38 Plan of Salvation. Within this movement, the largest organization of Apostolic Pentecostals is called the United Pentecostal Church International. Members of this organization often carry the title of "Pentecostal", whereas another church that is not affiliated with the United Pentecostal Church (UPCI) but still hold to the same doctrinal beliefs will sometimes carry the title "Apostolic", simply implying their church's independence and no affiliation with any certain organization.