When do we use <b> and <strong>? Whats the main difference between those?

Answer 1

There hardly is a difference other than the name. <strong> defines important text, and <b> just adds weight to data, and still could be important. I wouldn't worry too much about which one you use, but some search spiders consider <strong> more important than <b>.

Answer 2

When blind people look at a website, all the text is spoken to them. If you use <b>, the voice program will not do anything differently when reading that text. But if you use <strong>, the voice program might speak the text differently—with emphasis, or in a different tone of voice. This is done to convey to the blind person that the text is important in some way.

Answer 3

Index bots (Google ones for instance) are looking for <strong> tag as if they were some kind of keyword of your site. Then when someone types word that is indexed, your site will show higher in searched list, than ones with same word but without <strong> tag. But you have to know when and where use it, because over use can get you search ban in google for few days ^^

Answer 4

while <b> and <i> stand for bold and italic <strong> and <em> define that the text is important