A language exchange is when you find a language partner who has complementary language skills to you.
For example, you speak English and are learning Spanish, so you should find a language partner who speaks Spanish and is learning English. When you find a language partner who fits your language needs, you can add them as a new Friend.
After you become friends and agree to become language partners you can arrange a time for language exchange. Language exchanges are free and informal. If you and your partner are at an intermediate or advanced level, you can spend a longer time speaking in each language.
You can also practice your writing by becoming penpals and write to each other through italki Messages.