What do you mean by string interpolation?

Only one-way data binding is possible with Angular’s string interpolation, popularly known as the moustache syntax. It’s a unique syntax that uses double curly brackets to represent component data. The JavaScript expressions that Angular must run to get the result, which can then be put into the HTML code, are included within the brackets. Furthermore, as part of the digest cycle, these expressions are updated and saved on a regular basis.