In slide view, text is edited inside a special text box called a placeholder. A placeholder displays as a box with dotted outlines. Typing your text into a placeholder is the easiest way to add text to a slide.
All standard layouts come with at least one placeholder per slide except the blank presentation.
Here is an example of editing a title inside the title placeholder. Here is the title placeholder before you enter your text. Click anywhere inside the placeholder and type your text. Press Esc to perform such operations to your placeholder as resizing it, move it around your slide or simply delete it.