Meta Title / Meta Descriotion / Meta Keywords Vs Google Algorithm

Generally We can see lot of difference of thoughts between about the following 

1. Meta Title
2. Meta Description
3. Meta KeyWord

For Meta title the number of text characters should not exceed 70 nos and for Meta Descriptions the text characters should less than 160 nos. Whether these  Algorithms are followed by everybody or with some deviations in these concepts How some leading  web sites are coming in the best Google page ranking  ?

Also importance of  Key words , Now a days no robots or crawlers or considering this or considering in a minimal level . With or without  Meta Key word what will be the impact.

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