Alibaba Cloud Products and Services
What to know
Alibaba Cloud's catalog is best learned by function, not by memorizing every SKU. Group services into compute (ECS instances and images, auto scaling, container service ACK, serverless Function Compute), storage (Object Storage Service OSS for unstructured objects, cloud disks and NAS for block/file, and archive tiers), networking (VPC, vSwitches, security groups, SLB/ALB load balancing, EIP, CEN for multi-VPC and hybrid connectivity, Express Connect for dedicated lines), database (ApsaraDB RDS, PolarDB, Redis, MongoDB, Tablestore), and management/security (RAM for identity and permissions, CloudMonitor, ActionTrail, WAF, Anti-DDoS).
Traps to watch
Questions love near-miss pairings. OSS is object storage and is not a mountable filesystem for databases; NAS is. Security groups are stateful instance-level firewalls inside a VPC; SLB distributes traffic but is not a firewall. RAM controls who can call APIs; a security group controls what network traffic reaches an instance. PolarDB is a cloud-native database with storage-compute separation and read replicas, distinct from classic RDS. CEN connects networks; Express Connect is the physical dedicated line. Also note regionality: most resources are region-scoped, and cross-region replication must be configured explicitly.
Rule of thumb
Ask "what is the primary job?" If it is storing files accessed by URL, choose OSS. If it is a shared directory for many ECS instances, choose NAS. If it is low-latency block storage for one instance, choose a cloud disk. Match the service to the job before comparing features.
Worked example
A team needs a website with static images, a relational database, and horizontal scaling. Answer: OSS for images (optionally behind CDN), ApsaraDB RDS or PolarDB for the database, and SLB plus Auto Scaling across ECS instances in multiple vSwitches/zones.