Bptt - What is truncated Gru and BPTT?

Training contemporary recurrent neural networks, such the Long Short-Term Memory network, involves a variation of the Backpropagation approach called Backpropagation Through Time (BPTT). An improved form of BPTT, Truncated Backpropagation Through Time (BPTT) is better at solving sequence prediction problems with very lengthy sequences.