Yes, they are. Canva's stock media elements are all royalty-free, meaning you only pay for them once (with Canva Pro, your monthly fee covers unlimited licenses) and get to use them forever, including for commercial purposes like marketing and advertising.
How do I make a conference poster?
Important information should be readable from about 10 feet away.
Title is short and draws interest.
Word count of about 300 to 800 words.
Text is clear and to the point.
Use of bullets, numbering, and headlines make it easy to read.
Effective use of graphics, color and fonts.
Related Question how to make a poster online
How do I make a picture a poster online?
Step 1: Choose your poster size and type.
Step 2: Select your favorite photos.
Step 3: Upload your photos to Collage.com.
Step 4: Arrange your pictures in your favorite order.
Step 5 (Optional): Add custom backgrounds to your poster.
Step 6: Enjoy the poster you made with your own pictures.