Apple has unveiled new versions of its iPhones, which have done away with the traditional headphone socket. Instead the firm is promoting the use of its Airpods - new wireless earbuds, which offer new abilities but also need to be recharged on a regular basis. The latest iPhone launch is crucial for Apple, which has seen sales of the device slip amid ever fiercer competition. In July the company recorded its second consecutive quarter of revenue decline, breaking a streak of uninterrupted growth since 2003. Check out the video to see how Apple have evolved the iPhone over time.