You may download SQL Server 2017 versions from here.
Download link:
https://www.microsoft.com/en-us/sql-server/sql-server-downloads
Three options are available as follows:
Trial (time limited enterprise edition)
Developer
SQL express
DownlaodSQLServerDev2017_00
DownlaodSQLServerDev2017_01
DownlaodSQLServerDev2017_02
Microsoft describes this product as follows:
Industry-leading performanceTake advantage of breakthrough scalability, performance, and availability for mission-critical, intelligent applications and data warehouses.
Least vulnerableEnhance security with encryption at rest and in motion. SQL Server is the least vulnerable database over the last 7 years in the NIST vulnerabilities database.
Real-time intelligenceReason over any data and gain transformative insights for your business with real time analytics at up to 1M predictions/second.
End-to-end mobile BITransform data into actionable insights. Deliver insights on any device online or offline at one-fifth the cost of other self-service solutions.
Any application, anywhere Build modern applications using any data, any language--on-premises and in the cloud, now on Windows, Linux, and Docker containers.
LanguagesEnglish, German, Spanish, Japanese, Italian, French, Russian, Chinese Simplified, Chinese Traditional, Portuguese Brazil, Korean
Editions
SQL Server 2017 | 64-bit ISO for Windows
SQL Server 2017 | 64-bit CAB for Windows
Other Distributions:
Windows Container Image on Docker Hub: https://hub.docker.com/r/microsoft/mssql-server-windows/
Linux: SQL Server 2017 on Linux and Windows page.