There are a few alternatives to spanners, each with their own pros and cons.
Adjustable wrenches (also known as monkey wrenches) are very similar to open-ended spanners but the profile size can be changed. This means one tool can be used on multiple fastener sizes without having to find and swap spanners. On the other hand, adjustable spanners aren’t as strong as open-ended spanners.
Socket ratchets have interchangeable box-style heads, called sockets, allowing one tool to be used on multiple fastener shapes and sizes. Each socket has a fixed profile.
Torque wrenches are precision tools which tighten a fastener to a set tightness. Most torque wrenches use interchangeable sockets but some have one profile and a pre-determined torque.
Breaker bars are heavy-duty tools often with interchangeable sockets. They are excellent for large, strong fasteners as they have a long reinforced shaft, providing excellent leverage.
Slogging spanners are reinforced spanners (usually open-ended or ring spanners) designed to be used with a hammer to knock the end of the shaft and turn the fastener.