Text is the design of letters/numbers by using fonts like comic sans, Myrmid Pro, etc. Fonts can helps us identify specific texts, logos, etc. People may have a favourite one they use. For example I like using DFGothic-EB.
Type is when the letters/numbers are Italic, bold, underline, sizing, leading, kerning ,etc. Any product with text usually uses type to neat up spacing and line spacing for the pieces of texts. Italics is when the text is slightly shifted rationality to make it stand out for note, etc. Bold is when text is a bit more thicker and darker so it can been seen from first look. Underline is when text has a line below it, usually used for titles. Sizing is the size of the letters and numbers. It can be a small 9 size or a big 15 size. Leading is the space between each of the lines. Kerning is how close each of the letters/numbers are together. They could be close or far away from each letters.
These features of text and type can affect your final product by maybe making it easier to read or more eye catching if on a poster,etc. How to edit Texts and Text Types in both Photoshop and Illustrator is by the Tool bar at the top. For a more details and more customisable tab, go to Windows > Type > Character (go to Windows > Character).
We can also make custom text with pre-existing fronts. To do this, Select letters/numbers, then go to Object > Expand to make the text editable by expanding it to make it have points. Now we can edit it from each point by using the convert anchor point tool or delete/add anchor point tools. We can even use the points to transform and distort it to make new shapes for the text. Editing text may be good for originality a title , text in general. Custom text shaping may also affect your poster, media, etc.