The @ indicates the level of clocking.
5.0 in the example will usually mean a multiplier of 50x the base clock.
But clock does not mean all.
5.0 on a 11700K will do some 20% more work per clock than the previous gen 10700K
Also, clock does not necessarily apply to all cores concurrently.
Current turbo methods will increase the clock on a couple of cores if conditions permit and the remaining cores may run at much less.