What is mean by [1 -1] Filter?
I have the same book as you. :-) 

The [1 -1] filter is a a simple differentiator, also known as, the Haar mother wavelet. You need to understand convolution to understand what he is saying. On the first level, you convolve your signal with [1 -1]. Then on the next level, you convole your signal with [1 0 -1], etc. That is all the CWT is doing. (Look at convolution first). If you understand that well, you can understand CWT very easily.