What sets Web $2\mathrm{.}0$ apart from Web $1\mathrm{.}0?$

$2\mathrm{.}0$ is two$-$way

$1\mathrm{.}0$ was too slow

$2\mathrm{.}0$ uses IPv$6$

$1\mathrm{.}0$ was not secure

$2\mathrm{.}0$ started with social networks