what's the difference between these two series?

1.$\displaystyle 1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{n}-\frac{1}{n+1}+\frac{1}{n+1}-...$

2.$\displaystyle (1-\frac{1}{2})+(\frac{1}{2}-\frac{1}{3})+...+(\frac{1}{n}-\frac{1}{n+1})+...$

i think i understand how the 2nd one goes , but i don't get the first one. what difference does that last term make? and like in the 2nd one, the $\displaystyle (\frac{1}{n}-\frac{1}{n+1})$towards the end gives the general term. but $\displaystyle \frac{1}{n}-\frac{1}{n+1}+\frac{1}{n+1}$ doesn't seem like the general term for the 1st series.