What buyers should know about push to talk plans

It might be hard to believe but cell phones, also known as mobile phones, have been around since 1973. Cell phones were not very popular, unlike today's smartphones, and at that time they were basically status symbols for rich busy businessmen. 
Cell phones and smartphones really took off in popularity for the average consumer in the mid-1990s. Smartphones, or cell phones, went from being a luxury item for the in-crowd, to a necessity most people couldn't do without. Cellular plans varied in different features they offered consumers such as unlimited minutes, and data plans. 

The newest service cellular companies are offering Push-to-Talk Plans, which specifically target the business user. Many people haven't heard of Push-to-Talk communication plans. What is a push to talk communications plan, and how can phone plan shoppers understand and choose a plan that meets their needs?