{var%20f='http://v.t.sina.com.cn/share/share.php?appkey=1515056452',u=z||d.location,p=['&url=',e(u),'&title=',e(t||d.title),'&source=',e(r),'&sourceUrl=',e(l),'&content=',c||'gb2312','&pic=',e(p||'')].join('');function%20a(){if(!window.open([f,p].join(''),'mb',['toolbar=0,status=0,resizable=1,width=440,height=430,left=',(s.width-440)/2,',top=',(s.height-430)/2].join('')))u.href=[f,p].join('');};if(/Firefox/.test(navigator.userAgent))setTimeout(a,0);else%20a();})(screen,document,encodeURIComponent,'','','https://www.manongdao.com/data/attach/logo/logo.png', '推荐 戒情不戒烟 的问题《Bootstrap - about fonts files (.eot .svg .ttf .wof》','https://www.manongdao.com/q-502500.html','页面编码gb2312|utf-8默认gb2312'));){kind=link}
In the fonts folder of Bootstrap 3, we can see those files:
- glyphicons-halflings-regular.eot
- glyphicons-halflings-regular.svg
- glyphicons-halflings-regular.ttf
- glyphicons-halflings-regular.woff
- glyphicons-halflings-regular.woff2
Are they all the same files converted in different formats? Are they all necessary? What is the role/usage of each file?
They are included because each font was created to solve different problems. Woff and woff2 are the newest formats which were designed to stop font piracy. Svg is also a newer format which is a vector file and used on iOS mobile devices. Tff and eot are old school formats used by old browsers, but they allow anyone to download and use the font for free.
Short answer: They are all included for multi-version cross-browser compatibility.
See: Why should we include ttf, eot, woff, svg,... in a font-face