A logo’s design is for immediate recognition, inspiring trust, admiration, loyalty, and an implied superiority.
Let me explain why you shouldn’t be creating logos in Photoshop, why it’s important to create them in a vector based program (like Illustrator) and why that is important.
Photoshop is a Raster based program. Illustrator is a Vector based program.
Raster images are composed of pixels.
Common raster file types include JPG and PNG.
Vector images are made of hundreds of thousands of tiny lines and curves (or paths) to create an image. It is made out of shapes and lines that can be scaled infinitely
Common vector file types include EPS and PDF.
Example: 
Using Illustrator means your logo will be a vector object which is not part of a bitmap
While both programs here ‘can’ create a logo, you need to think about maintainability and uses of your logo. While its initial sizes may be predefined a logo needs to be resized and reshaped accordingly as it’s likely to be used many times on many different materials.
Top 3 Reasons you should start using Illustrator for your Logo.
Scaling
- Vector (Illustrator) logos are also scalable in size allowing them to be enlarged to fit the side of a Building or reduced to the size of a business card without losing quality.
Flexiable
2. You can save vector files as JPGs, PNGs, but you can’t do it the other way around and get all of the file types you need from a raster (Photoshop) logo.
Visual Branding
3. A logo is an important part of your company’s brand and makes a significant impact on a company’s public perception. Weak Branding = Missed Opportunities
A weak or negative online brand will cost you.
We make judgments about businesses credibility based on their design.
You know exactly what I’m talking about
We’ve all done this.
If you have an outdated or unappealing brand, chances are, your website visitors will be left with a bad first impression about your business.