在自定义指令的范围绑定中使用符号“@”、“&”、“=”和“>”:AngularJS

I have read a lot about the use of these symbols in the implementation of custom directives in AngularJS but the concept is still not clear to me. I mean, what does it mean if I use one of the scope values in the custom directive?I have read a lot about the use of these symbol