"Illustrator" is a crucial tech skill in the creative industry's digital realm. It is a vector graphics editor developed by Adobe Systems. Having proficiency in Illustrator means you are capable of creating and editing vector graphic images, diagrams, charts, logos, and illustrations. It's an indispensable skill when it comes to graphic design, digital artistry, marketing, and advertising.

Proficiency in Illustrator involves the ability to design, edit, and transform vector graphics, the capability to use a wide array of tools for creating patterns, textures, and complex images while maintaining the graphic properties even after scaling. It also includes a solid understanding of layering processes, image sizing, and color theory combined with the know-how to incorporate typefaces, shapes, and lines effectively.

Working with Illustrator demands accuracy, creativity, attention to detail, and an unwavering commitment to visual excellence. It often involves collaboration with other professionals like content creators, marketers, project managers, and, obviously, other designers. Therefore, excellent team playing and communication skills are necessary in addition to technical proficiency.

Before one can master Illustrator, it's beneficial to have foundational knowledge and skills in related areas. Familiarity with graphic design principles, along with basic drawing skills, can be hugely helpful. A basic understanding of other Adobe Creative Suite software, such as Photoshop and InDesign, goes hand-in-hand with learning Illustrator as these software frequently complement each other in the workflow.

Lastly, learning Illustrator isn't solely about getting to grips with the software. It also includes developing an appreciation for design aesthetics and staying updated with the latest trends in digital art and graphic design. This continuous learning and adapting mindset is what can set you apart in the creative industry.